Add MESSAGE_RSOCKET_AUTHENTICATION (#728)

According to specification from https://github.com/rsocket/rsocket/blob/master/Extensions/Security/Authentication.md

Signed-off-by: linux_china <[email protected]>

Author: linux-china

rsocket-core/src/main/java/io/rsocket/metadata/WellKnownMimeType.java

@@ -73,6 +73,7 @@ public enum WellKnownMimeType {
 
   // ... reserved for future use ...
 
+  MESSAGE_RSOCKET_AUTHENTICATION("message/x.rsocket.authentication.v0", (byte) 0x7C),
   MESSAGE_RSOCKET_TRACING_ZIPKIN("message/x.rsocket.tracing-zipkin.v0", (byte) 0x7D),
   MESSAGE_RSOCKET_ROUTING("message/x.rsocket.routing.v0", (byte) 0x7E),
   MESSAGE_RSOCKET_COMPOSITE_METADATA("message/x.rsocket.composite-metadata.v0", (byte) 0x7F);