[UI rewrite] Xamarin.Forms (including Linux & Gtk# support) port

[StEvUgnIn]

I am proposing to port UWPX-Client to Xamarin Platform, so that we can add iOS, android, GNU/Linux support and macOS support (as preview through Gtk#, later using Xamarin.Mac).

[COM8]

In theory, this would be possible since UWPX is written rather flexible and replacing individual components (e.g. push, sockets, db, ...) for platform specific ones should be possible.

But, I do not have any experience with that and also I'd like to have a rather good working XMPP Client for one platform, before I start porting it to others as well.

Any thoughts about that?

[StEvUgnIn]

I think it would be wise to expect Microsoft might write a wrapper or a tool to port the project from UWP to Xamarin Forms