Add features to GUI (#757)

* controller image changes depending on the selected controller type

the new controller image assets are temporary until i get new ones

* Game list scans subdirs for games

* Key file existence check

* Only shows Program NCAs in Application list

* Change shown GUI columns without restarting

* Sort by column if you click on the column header

Columns are sorted as text so there are inaccuracies on some columns

* Fix sort on Time Played, Last Played and File Size columns

* Add ability to designate favourite games #1

TODO:
- Make fav games persistent
- Fix invisible check marks due to theme

* Add ability to designate favourite games #2

Also removed default theme

* Added a Windows specific build condition and a Linux bug fix

* bugfix

* Load metadata from JSONs

* Temp bug fix for MacOS

* lil clean up

* requested changes

* Misc fixes

* edited schema and config

* Show the TitleID of games on the title bar

* gui column config option have names

* Async loading of game list

* bugfix and cleanup

* thog's requested changes

* requested changes and cleanup

still need to fix the gtk seizure

* Fix issue where an ExeFS as a NSP didn't show up in the application list

* Minor fixes

* catch glib unhandled exceptions

* Make sure to do UI manipulation in the main thread

* Print path of invalid files

* Ac_k's requested changes

* Return of the dark theme

* move AboutInfo struct to another file

* sort usings

* changes

- gdkchan's requested changes that have been marked resolved
- made some structs internal as they aren't used outside of the GUI
- renamed Ryujinx.UI to Ryujinx.Ui to fit naming convention and folder structure
- fixed bug where controller type dropdown box is stretched

Ryujinx/Ui/GtkDialog.cs

@@ -0,0 +1,23 @@
+using Gtk;
+using System.Reflection;
+
+namespace Ryujinx.Ui
+{
+    internal class GtkDialog
+    {
+        internal static void CreateErrorDialog(string errorMessage)
+        {
+            MessageDialog errorDialog = new MessageDialog(null, DialogFlags.Modal, MessageType.Error, ButtonsType.Ok, null)
+            {
+                Title          = "Ryujinx - Error",
+                Icon           = new Gdk.Pixbuf(Assembly.GetExecutingAssembly(), "Ryujinx.Ui.assets.Icon.png"),
+                Text           = "Ryujinx has encountered an error",
+                SecondaryText  = errorMessage,
+                WindowPosition = WindowPosition.Center
+            };
+            errorDialog.SetSizeRequest(100, 20);
+            errorDialog.Run();
+            errorDialog.Dispose();
+        }
+    }
+}