fix: add more options for screen sharing frame rate

Currently, the maximum frame rate of screen sharing is only 25fps.
Add more options to increase the maximum frame rate.

This PR fixes issue #1851.

resources/qml/voip/ScreenShare.qml

@@ -97,7 +97,7 @@ Popup {
                 id: frameRateCombo
 
                 Layout.fillWidth: true
-                model: ["25", "20", "15", "10", "5", "2", "1"]
+                model: ["120", "90", "60", "50", "48", "30", "25", "20", "15", "10", "5", "2", "1"]
             }
 
         }