Changes GIF image thumbnail handling to direcly load via gd instead of
going through interventions own handling (which supports frames) since
we don't need animation for our thumbnails, and since performance issues
could arise with GIFs that have large frame counts.
For #5029
Updated image loading for intervention library to be via a specific
'initFromBinary' method to avoid being overly accepting of input types
and mechansisms.
For CVE-2023-6199
- Moved thumnbail loading out of repo into ImageResizer.
- Updated gallery and editor image handling to show errors where
possible to indicate memory issues for resizing/thumbs.
- Updated gallery to load image data in a per-image basis via edit form
for more resiliant thumb/data fetching. Data was previously provided
via gallery listing, which could be affected by failing generation
of other images.
- Updated image manager double click handling to be more pleasant and
not flash away the edit form.
- Updated editor handlers to use main URL when thumbs fail to load.
