[2.0.16] Upgrade planner incorrectly supports captive biter spawner

[Legitimate Teddy]

In the upgrade planner, any quality of captive biter spawner may be selected, but only on the "to" side of the planner.
On the "from" side, it simply doesn't appear at all.
Attempting to set a "from" filter while a "to" filter is set gives an empty selection list.

"To" selection list, captive spawner present.

11-09-2024, 23-52-25.png (263.24 KiB) Viewed 217 times

"From" selection list, captive spawner absent.

11-09-2024, 23-51-30.png (203.08 KiB) Viewed 217 times

Empty selection list on "from" while captive spawner is set on "to".

11-09-2024, 23-43-24.png (66.67 KiB) Viewed 217 times

[Rseding91]

Thanks for the report. Looking into this, this is a side effect of us deciding if destination values should exist without having a source entity. I don't see a simple answer to this so for now I'm putting this into minor issues.