### Godot version

4.0beta17

### System information

Linux Mint 21.1

### Issue description

When editing animations for the **frame** property of **Sprite2D**, the preview image does not respect the **region_rect** specified in the Sprite2D's properties.

Godot 4.0 (tested with alpha1 to beta17)
![Screenshot from 2023-02-05 21-19-29](https://user-images.githubusercontent.com/2348534/216868394-45a9dc42-ce4b-4b11-82cb-4491aea46d9b.png)

Godot 3.5
![Screenshot from 2023-02-05 21-19-43](https://user-images.githubusercontent.com/2348534/216868543-cff6eb60-a431-4138-8fa6-5c30a54de0e1.png)

As can be seen in the second screenshot, the region rect is applied to the key preview image in Godot 3.5, but is ignored in Godot 4.0.


### Steps to reproduce

Steps:

1. Set a region rect on a Sprite2D node
2. Add Sprite2D.frame as a track to an AnimationPlayer
3. Insert key
4. Key preview does not take region rect into account

### Minimal reproduction project

[MRP.zip](https://github.com/godotengine/godot/files/10637055/MRP.zip)

if (p_point.x > get_timeline()->get_name_limit() && p_point.x < get_size().width - get_timeline()->get_buttons_width()) {
		Ref<AudioStream> stream;
		Dictionary drag_data = p_data;
		if (drag_data.has("type") && String(drag_data["type"]) == "resource") {
			stream = drag_data["resource"];
		} else if (drag_data.has("type") && String(drag_data["type"]) == "files") {
			Vector<String> files = drag_data["files"];
			if (files.size() == 1) {
				String file = files[0];
				stream = ResourceLoader::load(file);
			}
		}
		if (stream.is_valid()) {
			int x = p_point.x - get_timeline()->get_name_limit();
			float ofs = x / get_timeline()->get_zoom_scale();
			ofs += get_timeline()->get_value();
			ofs = get_editor()->snap_time(ofs);
			while (get_animation()->track_find_key(get_track(), ofs, Animation::FIND_MODE_APPROX) != -1) { 
				ofs += 0.0001;
			}
			EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
			undo_redo->create_action(TTR("Add Audio Track Clip"));
			undo_redo->add_do_method(get_animation().ptr(), "audio_track_insert_key", get_track(), ofs, stream);
			undo_redo->add_undo_method(get_animation().ptr(), "track_remove_key_at_time", get_track(), ofs);
			undo_redo->commit_action();
			queue_redraw();
			return;
		}