Support pgoutput based logical replication

[gwax]

Is your feature request related to a problem? Please describe.
Not all cloud based postgresql PaaS providers support the installation of plugins or provide wal2json support, which prevents the use of LOG_BASED replication with pipelinewise-tap-postgres in those environments.

Describe the solution you'd like
Add support for the built-in pgoutput plugin that comes standard with PostgreSQL.

Describe alternatives you've considered
INCREMENTAL and FULL_TABLE replication are still possible, albeit slower and lacking deletes.