We need to attach a thread id to each upload that is made. The best way to do this would be on the `keyserver`, as this gives us the flexibility of shareable code betweewn the `web` and `native` clients. This also means we don't need to propagate the thread id from the individual clients to the `keyserver`.
Originally, I planned to put this query in `message-creator`, as mentioned in the Linear task. However, this seemed to cause some problems where the query was being executed prior to a container being assigned to an upload, thus the query found no results. To resolve this, I looked around for where we assign a container to each upload, and thought that this would be the best place to attach a `thread` to each upload.
Depends on D6467
https://linear.app/comm/issue/ENG-2871/attach-a-threadid-to-each-media-imagevideo-upload