Removing all "any" from back.

To do this, I used generic-type-guard package which generates both an interface AND a valid type guard from code.
With this, we are 100% sure that the messages we receive are validated at runtime!
The client cannot pass us an object that is invalid! \o/

back/src/Model/Websocket/SetPlayerDetailsMessage.ts

@@ -1,4 +1,8 @@
-export interface SetPlayerDetailsMessage {
-    name: string,
-    character: string
-}
+import * as tg from "generic-type-guard";
+
+export const isSetPlayerDetailsMessage =
+    new tg.IsInterface().withProperties({
+        name: tg.isString,
+        character: tg.isString
+    }).get();
+export type SetPlayerDetailsMessage = tg.GuardedType<typeof isSetPlayerDetailsMessage>;