Completely remove features related to Desktop Overlay

As of SteamVR 1.10.1 the overlay width feature has been implemented by
Valve in the standard settings.
OpenVR features related to overlay translation have been removed and the
main reason for including them (multi monitor setups) have been solved
by Valve giving each screen an individual overlay.

src/res/qml/common/mainwidget.qml

@@ -6,7 +6,6 @@ import "../utilities_page"
 import "../audio_page"
 import "../motion_page"
 import "../video_page"
-import "../desktop_overlay_page"
 import "../chaperone_page"
 import "../steamvr_page"
 

src/res/qml/desktop_overlay_page/DesktopOverlayPage.qml

@@ -1,40 +0,0 @@
-import QtQuick 2.7
-import QtQuick.Controls 2.0
-import QtQuick.Layouts 1.3
-import ovras.advsettings 1.0
-import "translation_left_right"
-import "translation_back_forwards"
-import "translation_up_down"
-import "desktop_size"
-import "../common"
-
-MyStackViewPage {
-    headerText: "Desktop Overlay"
-
-    content: ColumnLayout {
-        spacing: 18
-
-        MyText {
-            Layout.alignment: Qt.AlignHCenter
-            horizontalAlignment: Text.AlignHCenter
-            text: "Reopen overlay to apply."
-        }
-
-        SteamDesktopGroupBox {
-        }
-
-        SteamDesktopTranslationUpDown {
-        }
-
-        SteamDesktopTranslationBackForwards {
-        }
-
-        SteamDesktopTranslationLeftRight {
-        }
-
-        Item {
-            Layout.fillHeight: true
-        }
-
-    }
-}

src/res/qml/desktop_overlay_page/desktop_size/SteamDesktopGroupBox.qml

@@ -1,23 +0,0 @@
-import QtQuick 2.7
-import QtQuick.Controls 2.0
-import QtQuick.Layouts 1.3
-import ovras.advsettings 1.0
-import "../../common"
-
-FullWidthSliderBox {
-    headerMessage: "Desktop Overlay Width: (refresh dashboard to apply)"
-
-    lowerLimit: 0.0
-    upperLimit: 32.0
-    sliderStepSize: 0.5
-    kbUID: 601
-
-    function onValueChanged(value) {
-        DesktopOverlay.width = value
-        sliderText = value.toFixed(2)
-    }
-    function onComponentComplete() {
-        sliderValue = DesktopOverlay.width
-    }
-}
-

src/res/qml/steamvr_page/SteamVRPage.qml

@@ -5,7 +5,6 @@ import ovras.advsettings 1.0
 import "../common"
 import "camera"
 import "steamvrmisc"
-import "../desktop_overlay_page/desktop_size"
 
 MyStackViewPage {
     width: 1200
@@ -19,9 +18,6 @@ MyStackViewPage {
         CameraGroupBox {
         id:  cameraGroupBox}
 
-        SteamDesktopGroupBox {
-        }
-
         Item { Layout.fillHeight: true; Layout.fillWidth: true}
 
         RowLayout {