House cleaning (#3083)

* Clean Up

As discussed in discord this PR purges some empty forms and it's unused properties from the following files below.

achievementsettingswidget.ui:   <string>Form</string>
advancedsettingswidget.ui:   <string>Form</string>
audiosettingswidget.ui:   <string>Form</string>
biossettingswidget.ui:   <string>Form</string>
consolesettingswidget.ui:   <string>Form</string>
controllerbindingwidget.ui:   <string>Form</string>
controllerbindingwidget_analog_controller.ui:   <string>Form</string>
controllerbindingwidget_analog_joystick.ui:   <string>Form</string>
controllerbindingwidget_digital_controller.ui:   <string>Form</string>
controllerbindingwidget_guncon.ui:   <string>Form</string>
controllerbindingwidget_mouse.ui:   <string>Form</string>
controllerbindingwidget_negcon.ui:   <string>Form</string>
controllerglobalsettingswidget.ui:   <string>Form</string>
controllermacroeditwidget.ui:   <string>Form</string>
displaysettingswidget.ui:   <string>Form</string>
emptygamelistwidget.ui:   <string>Form</string>
emulationsettingswidget.ui:   <string>Form</string>
enhancementsettingswidget.ui:   <string>Form</string>
foldersettingswidget.ui:   <string>Form</string>
gamelistsettingswidget.ui:   <string>Form</string>
gamelistwidget.ui:   <string>Form</string>
generalsettingswidget.ui:   <string>Form</string>
postprocessingsettingswidget.ui:   <string>Form</string>

src/duckstation-qt/controllerbindingwidget_guncon.ui

@@ -22,9 +22,6 @@
     <height>400</height>
    </size>
   </property>
-  <property name="windowTitle">
-   <string>Form</string>
-  </property>
   <layout class="QGridLayout" name="gridLayout_2">
    <item row="0" column="2">
     <widget class="QGroupBox" name="groupBox">