Fixing "idle in transaction" sessions/connections

• As a result of disabling auto commit long idle transactions occurred since no commit is ever sent.
• The fix wraps prepared statements into a proxy, which will send a commit at the time the query is closed.
• See Discussion: confluentinc#466
• We also are able to disable the TableMonitor thread to avoid catalog queries to be long running as well.

Postgres Optimization

This change will introduce:

• disable autoCommit
• batch.max.rows will be used to set fetchSize