[FEATURE] Make `player_maintenance` sql routine use prepare statements instead of hardcoded `DAY` intervals!

[proditis]

Right now we only support DAY intervals since our player_maintenance queries are like so

DELETE FROM `player` WHERE `status`=9 AND approval=4 AND `ts` < NOW() - INTERVAL player_delete_rejected_after DAY;

Make them use prepared statements instead so that we can support all the temporal intervals supported by the database (YEAR, MONTH, DAY, HOUR, MINUTE, SECOND etc)

Also update the configure form to use our match validation rule instead for the following fields

• player_require_approval
• player_delete_inactive_after
• player_delete_deleted_after
• player_changed_to_deleted_after
• player_delete_rejected_after