Fix up gutenberg and moby material metadata

[rgrp]

Material titles should be fixed up to include some info about source. That way the titles can be used on the site in an informative way.

• as part of this ticket should modify init_*data commands to support reloading (i.e. updating of existing entries with new metadata)

Cost: 0.5h

[rgrp]

Should not mess around with titles but should include an additional source field in model and use this as necessary. Will still require updates to metadata (and reloading of that materila) but as this requires model changes defer this into next release.

Also: not that important so downgrading priority.

[rgrp]

See r283, 289.