Big refactoring (server)

I used Intellij IDEA to automatically refactor code to achive 3 goals.
1) get rid of anonymouse classes, and replace the with lamba to get more readeable and clean code (like in TableWaitingDialog).
2) make effectively final  variables actually final to avoid inadvertent changes on it in further releases and keep objects as immutable, as possible.
3)  Get rid of unused imports (most of the changes) in whole project classes.

Mage.Server/src/main/java/mage/server/User.java

@@ -70,7 +70,7 @@ public class User {
 
     public enum UserState {
 
-        Created, Connected, Disconnected, Reconnected, Expired;
+        Created, Connected, Disconnected, Reconnected, Expired
     }
 
     private final UUID userId;