citra_qt: support multiple game directories

dist/qt_themes/default/default.qrc

@@ -12,6 +12,18 @@
 
         <file alias="16x16/lock.png">icons/16x16/lock.png</file>
 
+        <file alias="48x48/bad_folder.png">icons/48x48/bad_folder.png</file>
+      
+        <file alias="48x48/chip.png">icons/48x48/chip.png</file>
+
+        <file alias="48x48/folder.png">icons/48x48/folder.png</file>
+
+        <file alias="48x48/plus.png">icons/48x48/plus.png</file>
+      
+        <file alias="48x48/sd_card.png">icons/48x48/sd_card.png</file>
+      
         <file alias="256x256/citra.png">icons/256x256/citra.png</file>
+
+        <file alias="256x256/plus_folder.png">icons/256x256/plus_folder.png</file>
     </qresource>
 </RCC>

dist/qt_themes/default/icons/index.theme

@@ -1,10 +1,13 @@
 [Icon Theme]
 Name=default
 Comment=default theme
-Directories=16x16,256x256
+Directories=16x16,48x48,256x256
  
 [16x16]
 Size=16
+
+[48x48]
+Size=48
  
 [256x256]
 Size=256