Make HBaseIO.read() based on SDF by default

BEAM-4020 introduces HBaseIO reads based on SDF. So far the read() method still uses the Source based API because SDF does not support Dynamic Work Rebalancing (DWR) but the Source API of HBase does, so changing it means losing some functionality.

Since DWR is only supported by Dataflow once Dataflow supports SDF  **** DWR we can move the main read() function to use the SDF API and remove the Source based implementation. The rest of the runners already support Bounded based Reads (like HBase based on SDF does) via a default translation without DWR.

Imported from Jira [BEAM-4735](https://issues.apache.org/jira/browse/BEAM-4735). Original Jira may contain additional context.
Reported by: iemejia.