Add cooldowns to filters

Would be cool to have configurable cooldown for triggers, like if I already had an action after trigger wait for n seconds and don't do the same action before cooldown is over.

Start by locating the trigger and action handling, then find where filter configuration is defined and persisted. Determine how a configurable cooldown should apply between repeated actions, and verify that repeated triggers are suppressed only until the requested interval has elapsed.

Written by the indexing model from the issue text.