qt: add option to disable controller applet

- add checkbox to disable the controller applet UI
- when controller applet is disabled, use the yuzu-cmd fallback
  controller applet that applies controller config based on rules
- See https://github.com/yuzu-emu/yuzu/issues/8552 for some discussion

src/yuzu/configuration/configure_general.ui

@@ -103,6 +103,13 @@
             </property>
            </widget>
           </item>
+          <item>
+           <widget class="QCheckBox" name="toggle_controller_applet_disabled">
+            <property name="text">
+             <string>Disable controller applet</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </item>
        </layout>