This diff adds thumbhash creation step when uploading photos on web. The approach here is way simpler than on native. This works for both encrypted and non-encrypted media. The canvas code is based on [[ https://github.com/evanw/thumbhash/blob/4c3be1e7e8f8fee4911c70f77b6d15cce5b02775/examples/browser/index.html#L23-L31 | this example code ]].
In contrast to native, we can use [[ https://www.npmjs.com/package/thumbhash | thumbhash npm package ]] to avoid copying their code. Adding @ashoat because of this dependency