Review CREATE STREAM and CREATE MATERIALIZED VIEW syntax

[jfallows]

Describe the desired outcome from the user's perspective
As appdev, I want to create request-response APIs via zillabase simply in SQL.

Acceptance criteria

• Map as closely as possible to existing concepts
• Minimize introduction of zilla-specific complexity if possible

Additional context
Consider syntax such as CREATE ZSTREAM ... and CREATE ZSTREAM ... WITH ( reply_to= ... } etc.
Consider syntax such as CREATE ZTABLE ... to implicitly trigger source and sync to Kafka.
Consider syntax such as CREATE ZVIEW ... to implicitly trigger sync only to Kafka.

This implies SHOW ZSTREAMS, SHOW ZTABLES and SHOW ZVIEWS.

Consider syntax CREATE TABLE ... to pass through without implicitly triggering source and sync to Kafka.

Note: in each case with Z prefix, it represents an API we expose via Zillabase.

Tasks

• Update schemas to catalog z related queries into a separate schema and make public schema as defaul
• Support ZSTREAM, ZVIEW, and ZTABLE syntax
• Enhance ZSTREAM to support reply_to
• Support identity filtering in ZSTREAM, ZVIEW, and ZTABLE queries