Add /myroomnick slash command

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/JoinedRustRoom.kt

@@ -546,6 +546,12 @@ class JoinedRustRoom(
         }
     }
 
+    override suspend fun setOwnMemberDisplayName(displayName: String): Result<Unit> = withContext(roomDispatcher) {
+        runCatchingExceptions {
+            innerRoom.setOwnMemberDisplayName(displayName)
+        }
+    }
+
     override fun close() = destroy()
 
     override fun destroy() {