[BUG] summarize doesn't respect alignToFrom=true

[limpasha]

Describe the bug
When using query like /render?target=summarize(test_sum,"15min","sum","true")&from=-2003min&until=-3min we get resulting metric points not aligned to from, they are aligned to first metric point's timestamp.

CarbonAPI Version
commit 4eb7c03

Steps to repoduce

1. Have data like this (I show only non-zero values here)

 % curl '0:8081/render?target=pulse.test_sum&format=csv&from=-2003min&until=-3min' -s | egrep -v ',$'
"pulse.test_sum",2021-05-11 15:55:00,2
"pulse.test_sum",2021-05-11 15:57:00,100
"pulse.test_sum",2021-05-11 16:05:00,300
"pulse.test_sum",2021-05-12 08:42:00,300
"pulse.test_sum",2021-05-12 09:44:00,1
"pulse.test_sum",2021-05-12 09:48:00,1
"pulse.test_sum",2021-05-12 09:49:00,1
"pulse.test_sum",2021-05-12 10:10:00,1
"pulse.test_sum",2021-05-12 10:40:00,1
"pulse.test_sum",2021-05-12 10:41:00,1
"pulse.test_sum",2021-05-12 10:55:00,1
"pulse.test_sum",2021-05-12 11:26:00,1
"pulse.test_sum",2021-05-12 13:10:00,1

2. Make request

% date -u                                                                                                        
12.05.2021, 15:57:48 (UTC)
% curl '0:8081/render?target=summarize(pulse.test_sum,"15min","sum","true")&format=csv&from=-2003min&until=-3min'
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 15:55:00,402
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 16:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 16:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 16:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 16:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 17:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 17:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 17:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 17:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 18:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 18:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 18:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 18:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 19:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 19:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 19:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 19:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 20:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 20:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 20:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 20:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 21:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 21:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 21:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 21:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 22:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 22:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 22:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 22:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 23:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 23:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 23:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-11 23:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 00:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 00:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 00:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 00:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 01:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 01:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 01:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 01:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 02:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 02:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 02:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 02:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 03:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 03:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 03:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 03:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 04:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 04:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 04:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 04:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 05:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 05:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 05:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 05:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 06:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 06:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 06:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 06:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 07:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 07:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 07:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 07:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 08:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 08:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 08:40:00,300
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 08:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 09:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 09:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 09:40:00,3
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 09:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 10:10:00,1
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 10:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 10:40:00,2
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 10:55:00,1
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 11:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 11:25:00,1
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 11:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 11:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 12:10:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 12:25:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 12:40:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 12:55:00,
"summarize(pulse.test_sum,'15min','sum',true)",2021-05-12 13:10:00,1

3. As we can see, the first point's timestamp is derived from its actual timestamp (which is 2021-05-11 15:55:00), it didn't considered using from=-2003

CarbonAPI Configuration:

listen: "0.0.0.0:8081"
concurency: 20
cpus: 10
tz: ""
sendGlobsAsIs: true
maxBatchSize: 1000000
cache:
    type: "null"
idleConnections: 10
pidFile: ""
upstreams:
    buckets: 10
    timeouts:
        global: "60s"
        afterStarted: "10s"
        connect: "200ms"
    concurrencyLimit: 10
    keepAliveInterval: "30s"
    maxIdleConnsPerHost: 100
    tldCacheDisabled: true
    backends:
    backendsv2:
        backends:
          - groupName: "victoria"
            protocol: "victoriametrics"
            lbMethod: "broadcast"
            backendOptions:
                step: "60"
            servers:
                - "http://dev:5000"
expireDelaySec: 10