sql: initial insert support for table destination

[pdu-mn1]

Table is another main type of IO abstraction in Samza which supports both read and write (optional). For the table that do support writes, we should be able to allow SamzaSQL users to write a query to do that. One example is to insert into a database. The current code only supports inserting into a stream. This change adds the initial support for table insert operation.

[prateekm]

@pdu-mn1 Is this PR still relevant? If not, can you please close it? Thanks!