Allow multiple schemas to be exposed in one instance (#1450)

The schema to use can be selected through the headers `Accept-Profile` for GET/HEAD and `Content-Profile` for POST/PATCH/PUT/DELETE.

This is based on the https://www.w3.org/TR/dx-prof-conneg/ttps://www.w3.org/TR/dx-prof-conneg/ spec.

Also increase all memory tests by 1M(otherwise CI fails).

Co-authored-by: Mahmoud Kassem <MKassem@gk-software.com>
Co-authored-by: Mahmoud Kassem <mahmoud_k@mail.com>

test/fixtures/database.sql

@@ -1,3 +1,3 @@
 set client_min_messages to warning;
-DROP SCHEMA IF EXISTS test, private, postgrest, jwt, public, تست, extensions CASCADE;
+DROP SCHEMA IF EXISTS test, private, postgrest, jwt, public, تست, extensions, v1, v2 CASCADE;
 DROP TYPE IF EXISTS jwt_token CASCADE;