MOTECH-1379: Improve Commcare Performance

This commit improves commcare schema saving time. Instead of using one-to-many
relations in Commcare module we insert serialized objects into MOTECH database.
Additionally now we update Commcare schema only if needed.

The saving time is much better. More details in attached document on JIRA.

Unfortunately @Ignore doesn't work correctly and before fixing this problem,
we need also @NotPersistent annotation.

Change-Id: I62ac07427eadd35a0985170f4f261aa6073c35de