Add an option for using Timescaledb and not Postgres partitioning

[mkaranasou]

Since we've currently moved to Timescaledb and abandoned Postgres partitioning, we need to add this to the flow, so that every time a database is created, the user can chose between the two.

So instead of the partitioning script, after request_sets has been created, we need to run:

-- https://github.com/timescale/timescaledb/pull/61/commits/aecd681062e2710b861299b4f0aaaf1fa5eeef0b
SELECT create_hypertable('request_sets', 'stop', if_not_exists => true);