QDS-11947 Clean cached user project

This MR brings the following features;

• fix: clean the cached user project when it's removed from the cloud
• chore: move QrScanner to it's own class
• chore: rename the source files

android/AndroidManifest.xml

 <?xml version="1.0"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="io.qt.qtdesignviewer"
-    android:installLocation="auto" android:versionCode="26" android:versionName="1.2">
+    android:installLocation="auto" android:versionCode="27" android:versionName="1.2">
     <!-- %%INSERT_PERMISSIONS -->
     <!-- %%INSERT_FEATURES -->
     <supports-screens android:anyDensity="true" android:largeScreens="true"