Scanner: Image extraction is not working with GST1.0

[dublok]

mopidy-local-images does not extract the cover-art from music files anymore (since GST1.0).

This issue has two sides:

mopid
`convert_taglist'() ignores image tags.
https://github.com/mopidy/mopidy/blob/develop/mopidy/audio/tags.py#L52
I miss something like

            elif isinstance(value, Gst.Sample):
                # do the image things here
                result[tag].append(bytes(value.get_buffer())) # ???

mopidy-local-images
Does not support GST1.0.
https://github.com/mopidy/mopidy-local-images/blob/develop/mopidy_local_images/library.py#L171
GST1.0 Gst.Buffer has no data attribute

[tkem]

AFAICS, if image tags are added as bytes objects as proposed, mopidy-local-images would fall back on using the object "as is" when there's no data attribute.

[jodal]

Fixed by PR #1472.