rename debug_overlay to ui_debug_overlay in bevy_dev_tools (#12737)

# Objective

- Be more explicit in the name of the module for the ui debug overlay
- Avoid confusion and possible overlap with new overlays

## Solution

- Rename `debug_overlay` to `ui_debug_overlay`

crates/bevy_dev_tools/src/lib.rs

@@ -14,7 +14,7 @@ pub mod ci_testing;
 pub mod fps_overlay;
 
 #[cfg(feature = "bevy_ui_debug")]
-pub mod debug_overlay;
+pub mod ui_debug_overlay;
 
 /// Enables developer tools in an [`App`]. This plugin is added automatically with `bevy_dev_tools`
 /// feature.

examples/ui/ui.rs

@@ -21,7 +21,7 @@ fn main() {
 
     #[cfg(feature = "bevy_dev_tools")]
     {
-        app.add_plugins(bevy::dev_tools::debug_overlay::DebugUiPlugin)
+        app.add_plugins(bevy::dev_tools::ui_debug_overlay::DebugUiPlugin)
             .add_systems(Update, toggle_overlay);
     }
 
@@ -374,7 +374,7 @@ fn mouse_scroll(
 // The system that will enable/disable the debug outlines around the nodes
 fn toggle_overlay(
     input: Res<ButtonInput<KeyCode>>,
-    mut options: ResMut<bevy::dev_tools::debug_overlay::UiDebugOptions>,
+    mut options: ResMut<bevy::dev_tools::ui_debug_overlay::UiDebugOptions>,
 ) {
     info_once!("The debug outlines are enabled, press Space to turn them on/off");
     if input.just_pressed(KeyCode::Space) {