Disable keyboard controller input while swkbd is open (foreground) (#6646)

* Block input updates while swkbd is open in foreground mode

* Flush internal driver state before unblocking input updates

* Rename Flush to Clear and remove unnecessary attribute

src/Ryujinx/Input/AvaloniaKeyboard.cs

@@ -195,7 +195,7 @@ namespace Ryujinx.Ava.Input
 
         public void Clear()
         {
-            _driver?.ResetKeys();
+            _driver?.Clear();
         }
 
         public void Dispose() { }

src/Ryujinx/Input/AvaloniaKeyboardDriver.cs

@@ -94,7 +94,7 @@ namespace Ryujinx.Ava.Input
             return _pressedKeys.Contains(nativeKey);
         }
 
-        public void ResetKeys()
+        public void Clear()
         {
             _pressedKeys.Clear();
         }