Defer updating the animations Tree in SpriteFramesEditor to avoid crashes

[Rindbee]

Previously, clicking the LMB while renaming an animation could cause SpriteFramesEditor::_update_library(false) to be called during Tree::propagate_mouse_event(). This may cause a crash.

godot/scene/gui/tree.cpp

Lines 3783 to 3784 in 3ed4497

	blocked++;
	propagate_mouse_event(pos + theme_cache.offset, 0, 0, x_limit + theme_cache.offset.width, mb->is_double_click(), root, mb->get_button_index(), mb);

godot/scene/gui/tree.cpp

Lines 4290 to 4291 in 3ed4497

	TreeItem *Tree::create_item(TreeItem *p_parent, int p_index) {
	ERR_FAIL_COND_V(blocked > 0, nullptr);

godot/editor/plugins/sprite_frames_editor_plugin.cpp

Lines 1222 to 1223 in 3ed4497

	TreeItem *it = animations->create_item(anim_root);
	it->set_metadata(0, name);

We can defer updates to the editor interface to avoid calling Tree::create_item() at the wrong time.

Fix #79149.

[Rindbee]

A mechanism similar to update_tree() in EditorInspector is used.

[Rindbee]

Fix the edited animation not updating when undoing.

Before:

0.mp4

After:

1.mp4

[KoBeWi]

I can't really reproduce the crash to test the fix, but the changes look fine.

[akien-mga]

Thanks!