DRILL-4729: Add support for prepared statement implementation on server side
+ Add following APIs for Drill Java client
- DrillRpcFuture<CreatePreparedStatementResp> createPreparedStatement(final String query)
- void executePreparedStatement(final PreparedStatement preparedStatement, UserResultsListener resultsListener)
- List<QueryDataBatch> executePreparedStatement(final PreparedStatement preparedStatement) (for testing purpose)
+ Separated out the interface from UserClientConnection. It makes it easy to have wrappers which need to
tap the messages and data going to the actual client.
+ Implement CREATE_PREPARED_STATEMENT and handle RunQuery with PreparedStatement
+ Test changes to support prepared statement as query type
+ Add tests in TestPreparedStatementProvider
this closes #530
