We currently use the FileChooser from GTK, which is a bit mess. Instead of it we could use the native FileChooser from all specifics OS. This is what this PR attempt to fix.
It could be nice to get a test under linux since I've only tested it under Windows without any issues.
Fixes#2584
* Minor wording fixes
* Exit dialogue.
* Update MainWindow.cs
* Update DlcWindow.cs
* I found an actual typo for once.
* There we go.
* Fix
* Update MainWindow.cs
* MainWindow is done
* Update ControllerWindow.cs
* gui: Refactoring Part 1
* Fix ProfileDialog.glade path
* Fix Application.Quit assert
* Fix TitleUpdateWindow parent
* Fix TitleUpdate selected item
* Remove extra line in TitleUpdateWindow
* Fix empty assign of Enum.TryParse
* Add Patrons list in the About Window
* update about error messages
