the old event tap has several problems, like no proper priority support
or having to set accessibility permissions for mpv or the terminal.
it is now replaced by the new MediaPlayer which has proper priority
support and isn't as greedy as previously. this only includes Media Key
support and not any of the other features included in the MediaPlayer
framework, like proper Now Playing data (only set dummy data for now).
this is only available on macOS 10.12.2 and higher.
also removes some unnecessary redefines.
Fixes#6389
using the MPContext as ta parent was a bad idea and shouldn't be done in
any circumstances there because it only supposed to be for internal
usage. this had the undesired effect that the options group was freed
but still used since the MPContext is freed afterwards.
instead manually free options group.
this removes the direct access of the mp_vo_opts stuct via the vo struct
and replaces it with the m_config_cache usage. this updates the
fullscreen and window-minimized property via m_config_cache_write_opt
instead of the old mechanism via VOCTRL and event flagging. also use the
new VOCTRL_VO_OPTS_CHANGED event for fullscreen and border changes.
all the get_property_* usages were removed because in some circumstances
they can lead to deadlocks. they were replaced by accessing the vo and
mp_vo_opts structs directly, like on other vos.
additionally the mpv helper was split into a mpv and libmpv helper, to
differentiate between private and public APIs and for future changes
like a macOS vulkan context for vo=gpu.
der richter