Revert "Remove NOTIFICATION_ENTER_TREE when paired with NOTIFICATION_THEME_CHANGED"

This reverts commit 4b817a565cab8af648c88cfc7ab6481e86ee3625.

Fixes #64988.
Fixes #64997.

This caused several regressions (#64988, #64997,
https://github.com/godotengine/godot/issues/64997#issuecomment-1229970605)
which point at a flaw in the current logic:

- `Control::NOTIFICATION_ENTER_TREE` triggers a *deferred* notification with
  `NOTIFCATION_THEME_CHANGED` as introduced in #62845.
- Some classes use their `THEME_CHANGED` to cache theme items in
  member variables (e.g. `style_normal`, etc.), and use those member
  variables in `ENTER_TREE`, `READY`, `DRAW`, etc. Since the `THEME_CHANGE`
  notification is now deferred, they end up accessing invalid state and this
  can lead to not applying theme properly (e.g. for EditorHelp) or crashing
  (e.g. for EditorLog or CodeEdit).

So we need to go back to the drawing board and see if `THEME_CHANGED` can be
called earlier so that the previous logic still works?

Or can we refactor all engine code to make sure that:
- `ENTER_TREE` and similar do not depend on theme properties cached in member
  variables.
- Or `THEME_CHANGE` does trigger a general UI update to make sure that any
  bad theme handling in `ENTER_TREE` and co. gets fixed when `THEME_CHANGE`
  does arrive for the first time. But that means having a temporary invalid
  (and possibly still crashing) state, and doing some computations twice
  which might be heavy (e.g. `EditorHelp::_update_doc()`).

4 files changed, 9 insertions, 6 deletions

diff --git a/editor/debugger/editor_network_profiler.cpp b/editor/debugger/editor_network_profiler.cpp
index 185553cac0..8c18eba71d 100644
--- a/editor/debugger/editor_network_profiler.cpp
+++ b/editor/debugger/editor_network_profiler.cpp
@@ -40,6 +40,7 @@ void EditorNetworkProfiler::_bind_methods() {
 
 void EditorNetworkProfiler::_notification(int p_what) {
 	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE:
 		case NOTIFICATION_THEME_CHANGED: {
 			activate->set_icon(get_theme_icon(SNAME("Play"), SNAME("EditorIcons")));
 			clear_button->set_icon(get_theme_icon(SNAME("Clear"), SNAME("EditorIcons")));
diff --git a/editor/debugger/editor_profiler.cpp b/editor/debugger/editor_profiler.cpp
index 30197e6d8b..b49cab9df7 100644
--- a/editor/debugger/editor_profiler.cpp
+++ b/editor/debugger/editor_profiler.cpp
@@ -394,9 +394,10 @@ void EditorProfiler::_clear_pressed() {
 
 void EditorProfiler::_notification(int p_what) {
 	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE:
 		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED:
-		case NOTIFICATION_TRANSLATION_CHANGED:
-		case NOTIFICATION_THEME_CHANGED: {
+		case NOTIFICATION_THEME_CHANGED:
+		case NOTIFICATION_TRANSLATION_CHANGED: {
 			activate->set_icon(get_theme_icon(SNAME("Play"), SNAME("EditorIcons")));
 			clear_button->set_icon(get_theme_icon(SNAME("Clear"), SNAME("EditorIcons")));
 		} break;
diff --git a/editor/debugger/editor_visual_profiler.cpp b/editor/debugger/editor_visual_profiler.cpp
index df1a59cc99..6f3dd1793c 100644
--- a/editor/debugger/editor_visual_profiler.cpp
+++ b/editor/debugger/editor_visual_profiler.cpp
@@ -424,9 +424,10 @@ void EditorVisualProfiler::_clear_pressed() {
 
 void EditorVisualProfiler::_notification(int p_what) {
 	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE:
 		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED:
-		case NOTIFICATION_TRANSLATION_CHANGED:
-		case NOTIFICATION_THEME_CHANGED: {
+		case NOTIFICATION_THEME_CHANGED:
+		case NOTIFICATION_TRANSLATION_CHANGED: {
 			if (is_layout_rtl()) {
 				activate->set_icon(get_theme_icon(SNAME("PlayBackwards"), SNAME("EditorIcons")));
 			} else {
diff --git a/editor/debugger/script_editor_debugger.cpp b/editor/debugger/script_editor_debugger.cpp
index 1036561a47..fab211f18c 100644
--- a/editor/debugger/script_editor_debugger.cpp
+++ b/editor/debugger/script_editor_debugger.cpp
@@ -787,8 +787,8 @@ void ScriptEditorDebugger::_notification(int p_what) {
 			error_tree->connect("item_selected", callable_mp(this, &ScriptEditorDebugger::_error_selected));
 			error_tree->connect("item_activated", callable_mp(this, &ScriptEditorDebugger::_error_activated));
 			breakpoints_tree->connect("item_activated", callable_mp(this, &ScriptEditorDebugger::_breakpoint_tree_clicked));
-		} break;
-
+			[[fallthrough]];
+		}
 		case NOTIFICATION_THEME_CHANGED: {
 			skip_breakpoints->set_icon(get_theme_icon(skip_breakpoints_value ? SNAME("DebugSkipBreakpointsOn") : SNAME("DebugSkipBreakpointsOff"), SNAME("EditorIcons")));
 			copy->set_icon(get_theme_icon(SNAME("ActionCopy"), SNAME("EditorIcons")));