Deleting BigQueryWorkloadTester and updating related files.

[codecov[bot]]

Codecov Report

Merging #233 into dev will decrease coverage by 6.17%. The diff coverage is n/a.

@@             Coverage Diff             @@
##                dev    #233      +/-   ##
===========================================
- Coverage     82.97%   76.8%   -6.18%     
- Complexity      203     344     +141     
===========================================
  Files            34      34              
  Lines          1104    3250    +2146     
  Branches         66     266     +200     
===========================================
+ Hits            916    2496    +1580     
- Misses          179     663     +484     
- Partials          9      91      +82

Impacted Files	Coverage Δ	Complexity Δ
.../cloud/pontem/BaseCloudSpannerDatabaseRestore.java	87.93% <0%> (ø)	22% <0%> (?)
.../cloud/pontem/AvroCloudSpannerDatabaseRestore.java	0% <0%> (ø)	0% <0%> (?)
...loud/pontem/FormatStructAsGenericRecordFnTest.java	100% <0%> (ø)	10% <0%> (?)
...oud/pontem/AvroCloudSpannerDatabaseBackupTest.java	100% <0%> (ø)	3% <0%> (?)
...ntem/CloudSpannerDatabaseBackupIntegrityCheck.java	53.52% <0%> (ø)	8% <0%> (?)
...tem/FormatSpannerTablesListStructAsTextFnTest.java	100% <0%> (ø)	4% <0%> (?)
...java/com/google/cloud/pontem/TableInformation.java	87.71% <0%> (ø)	16% <0%> (?)
...CloudSpannerDatabaseRestoreIntegrityCheckTest.java	95.65% <0%> (ø)	5% <0%> (?)
...rc/test/java/com/google/cloud/pontem/UtilTest.java	92.3% <0%> (ø)	4% <0%> (?)
...e/cloud/pontem/BaseCloudSpannerDatabaseBackup.java	87.5% <0%> (ø)	16% <0%> (?)
... and 24 more