Avoids the need to duplicate this all over the place, and makes it
translator-friendly across the board.

We should display an error to the user if setting a user image for an
account fails, rather than continuing onwards.

This should be localizable, since it's user-facing text.

We can just make the function accept an arbitrary ProfileManager
reference and operate on that instead of tying the function to the class
itself. This allows us to keep the function internal to the cpp file and
removes the need to forward declare the UUID struct.

This is a static function so we can just perform an assignment directly.

Now that we can actually use std::optional on macOS, we don't need to
continue using boost::optional here.

Prevents bug where old username would remain if the new username was shorter in length.

Makes code consistent with our style of defaulting special member
functions where applicable.

Added ability to change username & language code in the settings ui. Added IProfile::Get and SET::GetLanguageCode for libnx tests (#851)

* Create a random console_id when config save_file is created

Added button in system config to refresh the console unique id

* Moved the connect for the button from .ui file to constructor of ConfigureSystem

* Added warning and info dialog
Fixup: Make use of qt5 style connects,
  renamed the refresh button,
  removed some duplicate code,
  changed random device and moved all to the generate function

* Changed the random generator to reflect what a real 3DS stores as console unique id
Fixup: Changed the warning message

* Fixup: Set and Create

* Fixup: Added console id label, therfore removed second message box

* Fixup: fixed the endianess

* Fixup: more endianness fixes

* Fixup: Endianness the 3rd

This makes clang-format useful on those.

Also add a bunch of forgotten transitive includes, which otherwise
prevented compilation.