Make GCSToBQLoadRunnable aware of which target BQ tables it should ma…

[anderseriksson]

For every connector using batch load to BigQuery the GCSToBQLoadRunnable class is responsible to look through the blobs in Google Cloud Storage and trigger jobs to load them into BigQuery.

Until now the GCSToBQLoadRunnable tried to load all blobs it could find in the bucket. If buckets are shared between connectors the GCSToBQLoadRunnable would still to load each blob into its target table. This caused blobs to be loaded into the target table several times, if there where several batch enabled BigQuery connectors running.

This PR suggests that the GCSToBQLoadRunnable only trigger load jobs for the blobs that are going to the target tables of its connector.

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[codecov-commenter]

Codecov Report

Merging #292 into master will decrease coverage by 0.18%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master     #292      +/-   ##
============================================
- Coverage     70.87%   70.68%   -0.19%     
  Complexity      301      301              
============================================
  Files            32       32              
  Lines          1538     1542       +4     
  Branches        164      167       +3     
============================================
  Hits           1090     1090              
- Misses          390      394       +4     
  Partials         58       58              

Impacted Files	Coverage Δ	Complexity Δ
...wepay/kafka/connect/bigquery/BigQuerySinkTask.java	58.94% <0.00%> (ø)	27.00 <0.00> (ø)
...ay/kafka/connect/bigquery/GCSToBQLoadRunnable.java	15.06% <0.00%> (-0.43%)	5.00 <0.00> (ø)