* hle: Some cleanup
This PR cleaned up a bit the HLE folder and the VirtualFileSystem one, since we use LibHac, we can use some class of it directly instead of duplicate things. The "Content" of VFS folder is removed since it should be handled in the NCM service directly.
A larger cleanup should be done later since there is still be duplicated code here and there.
* Fix Headless.SDL2
* Addresses gdkchan feedback
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