macosx: replaced deprecated 'UpdateSystemActivity' call with a modern, IOKit-based approach to prevent system sleep (close #6589)

This way, we can also differenciate between screen sleep (for video) and system sleep (for audio)

macosx: move code from CoreInteraction to the AppleScript class, since it was the only client using it

Fixes compiler warnings for a few methods without declarations called
before their definitions.
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

This allows to differentiate Title and Album, for example

macosx/MainWindow: added a fast-mode to show/hide the customizable buttons, since there is no need to do CoreAnimation stuff in a hidden window (close #7360)

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

(Though in practice, the only call site ignores the return value.)

In fact, the defaut values in the preferences are better than the
default value in the wizard. If the user really needs to change the
default for IPv4 multicast, (s)he can always save it in the
preferences more permantly.

And delete contributions from Götz Waschk

We do not know how to display it anyway

Ref: #6719
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>