[jdbc] Better support for Timescale features

[lujop]

Timescale support was added in #11091 but only for creating hypertables.
At least there are two other features of Timescale that fit extraordinarily well with OpenHab:

• data compression policies
• data retention policies

Both are defined per table using a select in a similar way to how the hypertable is created.
As there can be also other similar options and new possibilities in new timescale versions I think that will be useful to have a generic option to add extra DDL statements in native format when an Item table is created.

That way a user would be able to configure for example something like:

post_create_item_table_statements:

SELECT add_retention_policy('#tableName#', INTERVAL '24 hours');
SELECT add_compression_policy('#tableName#', INTERVAL '7 days');

If this approach is accepted I will try to contribute with a PR.

[openhab-bot]

This issue has been mentioned on openHAB Community. There might be relevant details there:

https://community.openhab.org/t/mysql-data-reduction/141319/2