- don't match 2 possible slaves between each others
- The slave name len should not be twice longer than the item name len.
(avoid matching "2016 - blabla.aac" with "20.mkv" for example)
The matching algorithm is still quite dumb and far from perfect. We should
detect item as slaves only if they have a language indication in their path
name.
Fixes#18913
test_media_has_slaves_from_player is deactivated for now since there is now way
to test inputs in a reliable way. Indeed, demux modules may depend on
configuration and systems libs.
TODO: test libvlc_media_player_add_slave