Support `pgsql-kafka` binding

[jfallows]

Note: consider direct support of CREATE TABLE etc here instead of exposing the concept of topics.

Mappings

• pgsql CREATE TOPIC command to KafkaCreateTopicsBeginEx plus catalog register new schema
• Support pgsql-kafka binding #1245
• pgsql ALTER TOPIC command to KafkaAlterConfigsBeginEx plus catalog register new schema #1308
• pgsql DROP TOPIC command to KafkaDeleteTopicsBeginEx #1307

Note: requires support for new Kafka...BeginEx, plus support for catalog register new schema.