### Godot version

v4.1.1.stable.official [bd6af8e0e]

### System information

Godot v4.1.1.stable - Ubuntu 22.04.2 LTS 22.04 - Vulkan (Forward+) - integrated Intel(R) UHD Graphics 615 (AML-KBL) () - Intel(R) Core(TM) i3-10100Y CPU @ 1.30GHz (4 Threads)

### Issue description

Summary: When editing the subregion of a StyleBoxTexture, it shows me the entire spritesheet of the Atlas texture, instead of the selected portion of the atlas, making it difficult (and non-intuitive) to correctly select the subregion I need. 

What I expect: I understand that the sub-region may be used to emulate the behavior of a nine-patch. So I would expect to see there the subregion that i selected previously from the Atlas as the texture to be shown.

I have only tested this in a Panel Container

### Steps to reproduce

I found this problem when doing these steps:

- Add a PanelContainer node
- In the inspector select Theme Overrrides -> Style -> new StyleBoxTexture
- In the texture of the StyleBoxTexture select new AtlasTexture
- Dropped the spritesheet in the Atlas of the AtlasTexture
- In Region of the AtlasTexture, selected Edit Region and drew the rectangle on the texture i want:
![image](https://github.com/godotengine/godot/assets/1207326/2e9624b1-63bc-4267-8d7f-59e82df7896e)

- Back in the StyleBoxTexture options, in Sub-Region, clicked on Edit Region to select the nine-patch region i need
- Here is where the region editor shows me the entire spritesheet and not the sub-texture i selected from the atlas. The image below shows the axis correctly positioned for the nine-patch to work, but it is not intuitive because it has to be positioned without seeing the correct texture, making it difficult to finetune for some textures.

![image](https://github.com/godotengine/godot/assets/1207326/a5023afd-7e4b-47c8-adfc-03fda7f6301b)


### Minimal reproduction project

N/A
case NOTIFICATION_READY: {
			zoom_out->set_icon(get_theme_icon(SNAME("ZoomLess"), SNAME("EditorIcons")));
			zoom_reset->set_icon(get_theme_icon(SNAME("ZoomReset"), SNAME("EditorIcons")));
			zoom_in->set_icon(get_theme_icon(SNAME("ZoomMore"), SNAME("EditorIcons")));
			vscroll->set_anchors_and_offsets_preset(Control::PRESET_RIGHT_WIDE);
			hscroll->set_anchors_and_offsets_preset(Control::PRESET_BOTTOM_WIDE);
			[[fallthrough]];
		}
		case EditorSettings::NOTIFICATION_EDITOR_SETTINGS_CHANGED: {
			panner->setup((ViewPanner::ControlScheme)EDITOR_GET("editors/panning/sub_editors_panning_scheme").operator int(), ED_GET_SHORTCUT("canvas_item_editor/pan_view"), bool(EDITOR_GET("editors/panning/simple_panning")));
		} break;
		case NOTIFICATION_VISIBILITY_CHANGED: {
			if (snap_mode == SNAP_AUTOSLICE && is_visible() && autoslice_is_dirty) {
				_update_autoslice();
			}
			if (!is_visible()) {
				EditorSettings::get_singleton()->set_project_metadata("texture_region_editor", "snap_step", snap_step);
				EditorSettings::get_singleton()->set_project_metadata("texture_region_editor", "snap_separation", snap_separation);
				EditorSettings::get_singleton()->set_project_metadata("texture_region_editor", "snap_mode", snap_mode);
			}
		} break;
		case NOTIFICATION_WM_WINDOW_FOCUS_IN: {
			
			
			cache_map.clear();
			_edit_region();
		} break;
	}
}
void TextureRegionEditor::_node_removed(Object *p_obj) {