Fixed RD-15252: Missing handling of TIMESTAMPTZOID

[bgaidioz]

An expression like NOW() evaluates to a TIMESTAMPTZ which fails to be converted and is sent as a string. Which for example breaks a Salesforce predicate.

WHERE date < NOW();

[info] simple_qual {
[info]   operator: LESS_THAN
[info]   value {
[info]     string {
[info]       v: "2025-03-26 15:40:46.640026+01"
[info]     }
[info]   }
[info] }

The patch ensures it's processed like a timestamp and the query doesn't send it as a string but as a plain timestamp.

WHERE date < NOW();

[info] simple_qual {
[info]   operator: LESS_THAN
[info]   value {
[info]     timestamp {
[info]       year: 2025
[info]       month: 3
[info]       day: 26
[info]       hour: 15
[info]       minute: 42
[info]       second: 3
[info]       nano: 301429000
[info]     }
[info]   }
[info] }

It strips the time zone from the timestamp (since we don't have support for time zones) after performing a translation to the local timezone.

• timestamp with time zone '2001-01-10 10:00:00+02:00' => DAS value 2001-01-10 09:00:00
• timestamp with time zone '2001-01-10 10:00:00+01:00' => DAS value 2001-01-10 10:00:00 (same time, Zurich)
• timestamp with time zone '2001-01-10 10:00:00+00:00' => DAS value 2001-01-10 11:00:00
• timestamp with time zone '2001-01-10 10:00:00-01:00' => DAS value 2001-01-10 12:00:00

Also fixed the missing microsecond value for timestamps in general.

WHERE x < timestamp '2001-01-10 10:12:34.123'

before:

[info]   value {
[info]     timestamp {
[info]       year: 2001
[info]       month: 1
[info]       day: 10
[info]       hour: 10
[info]       minute: 12
[info]       second: 34
[info]     }

after:

[info]   value {
[info]     timestamp {
[info]       year: 2001
[info]       month: 1
[info]       day: 10
[info]       hour: 10
[info]       minute: 12
[info]       second: 34
[info]       nano: 123000000
[info]     }

[miguelbranco80]

Need to put this one back.