[Task]: Add a way to limit concurrent crawler queue

[ikreymer]

Description

The concurrent crawl limit allows limiting how many crawls can be started at once for an org.
However, it currently still allows queuing unlimited crawls.
This is undesirable as it can exceed resources (and current concurrent check is not as efficient as it could be).

There should be an easy way to limit concurrent crawl queue to be X times the concurrent crawl limit.

Context

No response