Fixing rename for permitted subclasses.

[lahodaj]

Having something like:

sealed interface I permits Subtype {}
final class Subtype implements I {}

Renaming Subtype will not rename the identifier in the permits clause. This is because:

a) the write model (CausalDiff) does not support permits
b) the indexing does not include the permitted subclasses.

This PR is trying to fix both.

[lahodaj]

(Found a problem in the patch.)

[lahodaj]

Should be fixed now, and ready for review. Please let me know what you think!

[mbien]

this looks good as far as I can tell (thanks for the comments in CasualDiff).

merge conflict in apichanges.xml needs to be resolved + rebasing would be good to have a fresh CI run before integration.

[mbien]

I found a regression right after review :(

if you rename the interface, it will remove the permits section, this does not happen in NB 24

[lahodaj]

FWIW: the pre-existing methods now are a bit problematic, as if some code takes a ClassTree, and creates a new one from it using the old TreeMaker.Class/Interface method with permitted subclasses, the permitted subclasses will be lost. I don't see a good way around that.

So, I've tried to go through the whole NetBeans (production code), and fix what I could. Will push that shortly. I think I still need to make at least one pass through it, maybe add some tests, and maybe add some automated way to prevent use of the pre-existing methods. Will try to look at that as I can.