lib/media: remove deprecated stuff and debloat

This can now be determined unambiguously from the parsed status.

Note that this shifts all the values by one, but binary compatibility is
already broken anyway.

No functional change.

No functional changes.

This remove the old API for preparsed tracks.

Media parsing can occur on any instance, and in all likelihood, a freed
media is not being parsed by any instance.

Note: to cancel parsing, libvlc_media_parse_stop() can be used.

The prototype has changed anyhow, and the variants without options no
longer exist.