Animated GIFS in Chat

[rapterjet2004]

• fixes #3975

Paused to focus on offline support

🖼️ Screenshots

issue-3975-gifphy-2.webm

🚧 TODO

• [x] Fix Downloading to Cache
• [x] Make Gifs bigger
• [ ] Fix weird bug with images. Gifs are saved to cache, but the placeholder image is an unrelated photo.
  • [x] Debug the previewMessageViewHolder. isGif is working, it's a problem with the image loader.
  • [x] Debug the image loader. Image loader works fine, its the link that's an Image. But getting the gif link leads to an SSL exception -_-.
  • [ ] Debug the GifImageView. Perhaps it's saving previous image state, which could be messing things up.

🏁 Checklist

• [ ] ⛑️ Tests (unit and/or integration) are included or not needed
• [ ] 🔖 Capability is checked or not needed
• [ ] 🔙 Backport requests are created or not needed: /backport to stable-xx.x
• [ ] 📅 Milestone is set
• [x] 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)