While the spec says that the hdlr box should be the first one, not all
implementations follow that. Actually look over all boxes in Meta to
find Hdlr.
Also add a test for such weirdly-formatted box
Change the way unknown MetaBox is stored: store a list of boxes instead
of raw bytes
Co-authored-by: Alfred Gutierrez <alfg@users.noreply.github.com>
This introduces the 'Metadata' trait to enable access
to common video metadata such
title, year, cover art and more.
Reading 'title', 'description', 'poster' and 'year'
metadata is implemented here.
