This mostly fixes `key-order` warnings around
`block` statements.

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#no-changed-when

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1939

Instead of passing the connection string, we can now pass a name of a
variable, which contains a connection string.

Both are supported for having extra flexibility.

This can be used by various bridges, etc., to import an SQLite
(or some other supported) database into Postgres.