[hle,display,overlay,starter,hid] add overlay functions, starter applet (initially), HID handheld for system applets and fw21 stubs (#3080)

Adds fully functional overlay display.
- Enable Overlay Applet via "View" -> "Enable Overlay Display Applet"
- Open the overlay by pressing the home button for over 1s
- Can adjust volume
- Can toggle airplane mode (if on WiFi, maybe if overlay is enabled pretend to be on WiFi?)
- Future TODO(?): Adjust Brightness implementation for host system
- Inputs are properly registered. e.g. if overlay open, application does not register inputs.

You can control volume and airplane mode outside of the emulator window

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3080
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: Maufeat <sahyno1996@gmail.com>
Co-committed-by: Maufeat <sahyno1996@gmail.com>

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/BooleanSetting.kt

@@ -72,7 +72,8 @@ enum class BooleanSetting(override val key: String) : AbstractBooleanSetting {
     DEBUG_FLUSH_BY_LINE("flush_line"),
     USE_LRU_CACHE("use_lru_cache"),
 
-    DONT_SHOW_DRIVER_SHADER_WARNING("dont_show_driver_shader_warning");
+    DONT_SHOW_DRIVER_SHADER_WARNING("dont_show_driver_shader_warning"),
+    ENABLE_OVERLAY("enable_overlay");
 
 
 //  external fun isFrameSkippingEnabled(): Boolean

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/view/SettingsItem.kt

@@ -849,7 +849,14 @@ abstract class SettingsItem(
                     descriptionId = R.string.airplane_mode_description
                 )
             )
+
+            put(
+                SwitchSetting(
+                    BooleanSetting.ENABLE_OVERLAY,
+                    titleId = R.string.enable_overlay,
+                    descriptionId = R.string.enable_overlay_description
+                )
+            )
         }
     }
 }
-

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -491,6 +491,7 @@ class SettingsFragmentPresenter(
         sl.apply {
             add(IntSetting.SWKBD_APPLET.key)
             add(BooleanSetting.AIRPLANE_MODE.key)
+            add(BooleanSetting.ENABLE_OVERLAY.key)
         }
     }
     private fun addInputPlayer(sl: ArrayList<SettingsItem>, playerIndex: Int) {

src/android/app/src/main/res/values/strings.xml

@@ -1125,7 +1125,7 @@
 
     <!-- Applet Modes -->
     <string name="applets_menu">Applets</string>
-    <string name="applets_menu_description">(WIP) Change applet frontends and settings</string>
+    <string name="applets_menu_description">Change applet frontends and settings</string>
 
     <string name="applet_hle">Custom Frontend</string>
     <string name="applet_lle">Real Applet</string>
@@ -1135,6 +1135,9 @@
     <string name="airplane_mode">Airplane Mode</string>
     <string name="airplane_mode_description">Passes Airplane Mode to the Switch OS</string>
 
+    <string name="enable_overlay">Enable Overlay Applet</string>
+    <string name="enable_overlay_description">Enables Horizon\'s built-in overlay applet. Press and hold the home button for 1 second to show it.</string>
+
     <!-- Licenses screen strings -->
     <string name="licenses">Licenses</string>
     <string name="license_fidelityfx_fsr" translatable="false">FidelityFX-FSR</string>