Rework save format and punishment manager

- Punishments are now saved as JSON in files named after their targets
- Each punishment type now has its own Java class
- Each file contains a list of JSON objects that is updated every time something changes (e.g. player muted, banned or unbanned)
- Punishments have a unique ID now; if something changes, the new version is added to the list and overwrites the old version
- 'Undo' has been renamed to 'cancel'
- You can no longer mute or ban players if they are already muted or banned

src/main/java/de/shiewk/smoderation/paper/util/PlayerUtil.java

@@ -28,4 +28,12 @@ public final class PlayerUtil {
             return Bukkit.getPlayer(uid);
         }
     }
+
+    public static UUID uuidFromString(String string) {
+        if (string.length() == 36) {
+            return UUID.fromString(string);
+        } else {
+            return UUID.fromString(string.replaceFirst("(.{8})(.{4})(.{4})(.{4})(.{12})", "$1-$2-$3-$4-$5"));
+        }
+    }
 }