feat(core): mark AppHandle::restart and process::restart as diverging functions

[amrbashir]

closes #10160

[Legend-Master]

Should we also mark exit?

[amrbashir]

good call

[amrbashir]

actually it is not possible for exit since it only sends a request to exit, and users are free to prevent that, so we need to either leave it as is or introduce a new method called request_exist and mark the current one as diverging

[Legend-Master]

That makes sense, I only saw that if error process::exit part and assumed it will always exit, seems like it's detecting the error of sending the message