♻️ Refactor websocket layer.

This commit replaces rj9a with funcool/yetti ring adapter.
Cleans the websocket api and makes it fully asynchronous.
Also a common websocket protocol abstraction that will allow
more easy path for creating new websocket based services.

backend/scripts/repl

@@ -6,7 +6,7 @@ export OPTIONS="
        -A:jmx-remote:dev \
        -J-Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager \
        -J-Dlog4j2.configurationFile=log4j2-devenv.xml \
-       -J-XX:+UseShenandoahGC \
+       -J-XX:+UseZGC \
        -J-XX:-OmitStackTraceInFastThrow \
        -J-Xms50m -J-Xmx512m";