stork-tool should create DB with pgcrypto

The issue was found during 1.1.0 sanity checks. Source

The stork-tool db-create command creates new postgres database, but does not create pgcrypto extension. The extension is created in one of the migrations but apparently it requires super-user role in Postgres. That causes the isc-stork-server to fail to start with a freshly created database. It is possible to run the migrations with the Stork tool, e.g.:

stork-tool db-up --db-user postgres

because postgres is a super-user role.

I recommend that we add CREATE EXTENSION pgcrypto step to the db-create command. In fact, that had been an initial plan but we removed that during the ticket review. Anyway, it is a non-blocking issue because there are tons of workarounds.