Fix bounties(and potentially other things) running out of ids (#32700)

Fix bounties(and potentially other things) running out of ids (#32700)

* Make NameIdentifier Ids get refreshed after round restarts

Before this commit the existing values would just get shuffled.
This means that eventually the server would run out of ids to give to
new entities for different groups. As a result everything would get id 0

* Comply with what seemingly is the convention for sawmills

* Make it impossible to insert a bounty with a duplicate id

* Reduce duplication

* Remove unused sawmill

* Fix rustbrain and skill issue

* Aaaa

* Apply suggestions from code review

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Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>