Add explicit support for materialized views

[CommanderStorm]

We currently don't have a test case if we handle Postgres' materialized views.

If we support this currently is questionable because for example when our query looks at comments, comments on the materialized views (relkind= 'm') are not looked at

martin/martin/src/config/file/postgres/resolver/scripts/query_available_tables.sql

Line 116 in 7b148d7

WHERE cls.relkind = 'r' OR cls.relkind = 'v'

Our test cases are located under /tests/test.sh and our table sources at /tests/fixtures/tables

[kunalsinghdadhwal]

@CommanderStorm I want to work on it can you assign it to me. Appreciate it

[CommanderStorm]

Awesome ♥️