ui/cocoa: add option to swap Option and Command

ui/cocoa: add option to swap Option and Command

On Mac OS X the Option key maps to Alt and Command to Super/Meta. This change
swaps them around so that Alt is the key closer to the space bar and Meta/Super
is between Control and Alt, like on non-Mac keyboards.

It is a cocoa display option, disabled by default.

Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gustavo Noronha Silva <gustavo@noronha.dev.br>
Message-Id: <20210713213200.2547-3-gustavo@noronha.dev.br>
Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-Id: <20220306121119.45631-3-akihiko.odaki@gmail.com>
Reviewed-by: Will Cohen <wwcohen@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>