Rename ScrCpyServer to Server

The Server class is in package scrcpy, there is no need to repeat the
name in the classname.

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -2,9 +2,9 @@ package com.genymobile.scrcpy;
 
 import java.io.IOException;
 
-public final class ScrCpyServer {
+public final class Server {
 
-    private ScrCpyServer() {
+    private Server() {
         // not instantiable
     }