Rework avatars.

Now we have a concept of an avatar at the server, realm, and scene level
and we have the groundwork for a realm store. New uesrs no longer props,
they get a default avatar. New system supports gender
{male,female,neutral} and {child,adult}.

e2e/test-results/.last-run.json

@@ -1,4 +0,0 @@
-{
-  "status": "passed",
-  "failedTests": []
-}