Removed internal logic on permission handling

Related to https://git.gfz-potsdam.de/dynamicexposure/server-components/deployments/databases/-/merge_requests/1

Remove internal logic on creating the database, handling users and permissions.

\approve @ds @prehn

migrations/00001_create-initial-db.sql

--- Create the main database
-
-CREATE DATABASE obm_tiles
-    WITH 
-    OWNER = postgres
-    ENCODING = 'UTF8'
-    LC_COLLATE = 'en_US.utf8'
-    LC_CTYPE = 'en_US.utf8'
-    TABLESPACE = pg_default
-    CONNECTION LIMIT = -1;
-
--- Create a basic schema
-
-CREATE SCHEMA public
-    AUTHORIZATION postgres;
-
-GRANT ALL ON SCHEMA public TO PUBLIC;
-
-GRANT ALL ON SCHEMA public TO postgres;