* FileUpload: add sharex file support
Quick note, the settings seem to split pacal case with spaces for some reason,
so `ShareX` renders as `Share X`. This is stupid and im upset and I dont think
theres anything I can do about it
* FileUpload: use Headers object to construct HTTP headers
this allows uploads to Nest and E-Z to work on equibop/web,
and the proxy is hosted on workers so it should have good
uptime and latency.
i can send the code if you or creations want to host it
instead if that's preferable, since i know relying on too
many external apis is yucky
