Fixes#9949
Only calls `setTenorAPIKey` once we need it (when doing a search or getting trending).
Also caches the trending gifs so that they are only fetched once.
Makes the search and trending calls async by create an async tenor query async task.
Enable preview for gifs after enabling the gif functionality
Disable gif functionality if the preview was disabled
Addition fixes
- The gifs weren't checked if all images weren't enabled
- The subdomain wasn't checked for whitelisting if the main domain wasn't enabled
- Image clicking
- Dismiss asking for unfurling was not updating the state
Considerations
- Looked into having the "gif enabled" - "tenor unfurling" relation
embedded in the controller but it would require extensive refactoring
by implementing a data-model for unfurling whitelisted domains
Closes: #6829
Jonathan Rainville
Stefan