Setup database / grant schema priveleges

[ZakarFin]

Looks like with Postgresql 16 (at least on WSL Ubuntu with defaults on everything) it is also required to do:

grant all privileges on schema public to oskari;

after creating the database and the oskari user. The current docs lists only this:

GRANT ALL PRIVILEGES ON DATABASE oskaridb to oskari;

but looks like it's not enough. Without it the current Flyway version can't make the status-table with an error Message: ERROR: permission denied for schema public. Thought it also notes on log:

Flyway upgrade recommended: PostgreSQL 16.6 is newer than this version of Flyway and support has not been tested. The latest supported version of PostgreSQL is 15.