mxfdemux: Take temporal reordering from the index table into account

mxfdemux: Take temporal reordering from the index table into account

This is needed to know the PTS, without that we only know the DTS and
using that also for the PTS is wrong unless we have an intra-only codec.

If we can't get the temporal reordering from the index table, don't set
any PTS for non-intra-only codecs and let decoders figure out something.

https://bugzilla.gnome.org/show_bug.cgi?id=784027