[app-wiring-refactor]: Apply review comments:

- Add reference to original library in `FluentBuilder`.
- Change `I<Name>` notation to `<Name>Impl` notation.
- Move error config to test resources
- Add comment with config instruction
- Add config to the documentation

Mage.Server/src/main/java/mage/server/managers/ThreadExecutor.java

@@ -0,0 +1,16 @@
+package mage.server.managers;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.ScheduledExecutorService;
+
+public interface ThreadExecutor {
+    int getActiveThreads(ExecutorService executerService);
+
+    ExecutorService getCallExecutor();
+
+    ExecutorService getGameExecutor();
+
+    ScheduledExecutorService getTimeoutExecutor();
+
+    ScheduledExecutorService getTimeoutIdleExecutor();
+}