Add backoff and retry when KC BQ hits quota limit

[C0urante]

(Migrated from internal Jira issue DI-448)

We currently have a hard-coded sleep of 1000ms (BigQuerySinkTask.TABLE_WRITE_INTERVAL) for writes to each table. This is a performance penalty that's pretty expensive when running a bootstrap of a lot of data (we're behind in the log). During load testing, I was seeing 30000 rows (212 bytes each) take > 3 seconds to write to BigQuery using the streaming API. The single-writer performance in the BQ stream API seems to be in the 1-2 megs/sec range.

Eliminating this config will expose us to quota issues with BigQuery. They only allow 100,000 rows/sec/table. It's going to be really difficult for us to tune this properly using configuration in a distributed environment, since we'll have some number of writers distributed across multiple machines. I think the right approach is actually just to add back off and retry logic when we receive a quota_exceeded error. This will cause the tasks to automatically handle quota exceeded errors, and will allow us to go full throttle when bootstrapping data.

[mtagle]

Fixed in PR #40