clean up models

Signed-off-by: dom <githubaccount56556@proton.me>

lib/models_new/relation/data.dart

@@ -1,14 +1,12 @@
 import 'package:PiliPlus/utils/extension/iterable_ext.dart';
 
 class RelationData {
-  int? mid;
   int? attribute;
   int? mtime;
   List<int>? tag;
   int? special;
 
   RelationData({
-    this.mid,
     this.attribute,
     this.mtime,
     this.tag,
@@ -16,7 +14,6 @@ class RelationData {
   });
 
   factory RelationData.fromJson(Map<String, dynamic> json) => RelationData(
-    mid: json['mid'] as int?,
     attribute: json['attribute'] as int?,
     mtime: json['mtime'] as int?,
     tag: (json['tag'] as List<dynamic>?)?.fromCast(),