Delay escalator by a huge escalations table with Recovery operations

from ZBX-13137

There are cases in which you store them in the escalations table without the OK event.

Examples:

zabbix=> select count(*) from escalations where status=2;
  count  
---------
 1180124

The real problem is the "escalator busy 100%" in this situation.
Escalator's busy rate has increased and It's hard to notice the problem until the problem occurs.

Solution 1 (no need for development)
Delete a "recovery operation" actions or "all event manual close" can solves this problem. (escalation table datas is also deleted.)

And I also thought it's better to remove it from the escalations if really don't need to deal with "RECOVERY" by trigger settings. Problem of "escalator busy" is need improvement. Therefore, the additional improvements that require development are below.

Solution 2
With "OK event generation : None" and "Don't allow manual close" datas -> to be removed

Solution 3
With "OK event generation : None" and "Allow manual close" datas -> If possible, We need a solution that doesn't increase the escalator busy rate. (The best solution is not to store data in escalations.)

Solution 4 (New Features)
An additional feature that allows to automatically close (remove the old escalation data)