They are fundamentally different concepts, so should be represented as
such. Proto events are exchanged in /make_xxx calls over federation, and
made as "fledgling" events in /createRoom and general event sending.
*Building* events is a reasonably complex VERSION SPECIFIC process which
needs amongst other things, auth event providers, prev events, signing
keys, etc.
Requires https://github.com/matrix-org/gomatrixserverlib/pull/379
2b34f88fde