This adds support for sending blurhashes with images, which need to be
generated client-side. Quotient now supports this and the blurhash
implementation was also moved upstream.
This hasn't proven to be as useful as i had hoped:
- My arcane logic for determining logging categories is apparently broken
- It won't work with the logging by the new crypto sdk
- I never actually ended up looking at my own logs, or anyone else's
- It seems to cause crashes
