Allows updating the credentials of the announce session, thus allowing credentials changes to be reflected before citra restart. To avoid race conditions and web errors (you can only update the room that you created, i.e. changing credentials halfway will make it break), now you can only use the Citra Web Services settings when not hosting a public room.
These slots are only ever attached to event handling mechanisms within
the class itself, they're never used externally. Because of this, we can
make the functions private.
This also removes redundant usages of the private access specifier.
Instead, we make a proper registry class and house it within the main
window, then pass it to whatever needs access to the loaded hotkeys.
This way, we avoid a global variable, and don't need to initialize a
std::map instance before the program can do anything.
