Support for thumbnail size x-large and xx-large

Like defined in the Spec:

https://specifications.freedesktop.org/thumbnail-spec/thumbnail-spec-latest.html#DIRECTORY

That specially might be useful for hi-pdi screens

added 5. Thumbnails label

mentioned in issue tumbler#51 (closed)

Done on Tumbler's side: tumbler@5affdb5c

Remark: the request in #702 is likely to be even more topical with these sizes…

Well done @Tamaranch !

I'll take a look for the thunar part. Probably a rather simple change.

assigned to @alexxcons

mentioned in commit 9657a282

Done ... will work with tumbler master (or 4.17.0 soon), to be released in thunar 4.17.8

closed

mentioned in issue apps/catfish#74

mentioned in issue #735 (closed)

mentioned in merge request !303