feat: pgc index page

Closes #216

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

lib/models/bangumi/pgc_index/condition.dart

@@ -0,0 +1,70 @@
+class Condition {
+  List<Filter>? filter;
+  List<Order>? order;
+
+  Condition({
+    this.filter,
+    this.order,
+  });
+
+  Condition.fromJson(Map json) {
+    filter = (json['filter'] as List?)
+        ?.map((item) => Filter.fromJson(item))
+        .toList();
+    order =
+        (json['order'] as List?)?.map((item) => Order.fromJson(item)).toList();
+  }
+}
+
+class Order {
+  String? field;
+  String? name;
+  String? sort;
+
+  Order({
+    this.field,
+    this.name,
+    this.sort,
+  });
+
+  Order.fromJson(Map json) {
+    field = json['field'];
+    name = json['name'];
+    sort = json['sort'];
+  }
+}
+
+class Filter {
+  String? field;
+  String? name;
+  List<Values>? values;
+
+  Filter({
+    this.field,
+    this.name,
+    this.values,
+  });
+
+  Filter.fromJson(Map json) {
+    field = json['field'];
+    name = json['name'];
+    values = (json['values'] as List?)
+        ?.map((item) => Values.fromJson(item))
+        .toList();
+  }
+}
+
+class Values {
+  String? keyword;
+  String? name;
+
+  Values({
+    this.keyword,
+    this.name,
+  });
+
+  Values.fromJson(Map json) {
+    keyword = json['keyword'];
+    name = json['name'];
+  }
+}