Add VoIP support

Some reverse proxies have bugs or a misconfigured and return
uncompressed bodies with a compression header (i.e. some versions of
caddy, if you enable compression in synapse). This prevents nheko
breaking in those cases.

Add methods for SAS

Online key backup

This is needed for openssl 1.1. Sadly this breaks json_fwd.hpp
detection, so it was removed (for now at least).

Still causing MAC errors