Fix debugger tab runtime update

[razcore-rad]

fixes #203
supersedes #204

I left it on as a Draft PR because the realtime update is not ideal as it unregisters & re-registers the entire tree every node change which can be optimized + unit tests added.

Tested with a modified version of the project from #203:
BeehaveBranchBug.zip

2024-01-20_09-21-32.mp4

edit:
I noticed that all I have to do to update the tree is to re-register it, no other necessary unregister/register steps so I amended the last commit.

So what's left is unit testing.

[razcore-rad]

OK, I'm actually not entirely sure how to write a test for this since the example with the debugger is actually using an instance of the debugger tab at runtime where we already know register_tree() works so adding a scene where we call functions like this:

# test/debug/debugger_test_scene.gd
func _ready() -> void:
	# [...]
	beehave_tree.get_node("SequenceComposite/MockAction").queue_free()
	await get_tree().create_timer(1).timeout
	beehave_debugger_tab.register_tree(beehave_tree._get_debugger_data(beehave_tree))

Is meaningless.

[bitbrain]

Amazing work and nice approach - thanks for your contribution @razcore-rad