feat: session secondary

Closes #837

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

lib/grpc/dm.dart

@@ -0,0 +1,27 @@
+import 'package:PiliPlus/grpc/bilibili/community/service/dm/v1.pb.dart';
+import 'package:PiliPlus/grpc/grpc_repo.dart';
+import 'package:PiliPlus/http/loading_state.dart';
+import 'package:fixnum/fixnum.dart';
+
+class DmGrpc {
+  static Future<LoadingState<DmSegMobileReply>> dmSegMobile({
+    required int cid,
+    required int segmentIndex,
+    int type = 1,
+  }) async {
+    final res = await GrpcRepo.request(
+      GrpcUrl.dmSegMobile,
+      DmSegMobileReq(
+        oid: Int64(cid),
+        segmentIndex: Int64(segmentIndex),
+        type: type,
+      ),
+      DmSegMobileReply.fromBuffer,
+    );
+    if (res['status']) {
+      return LoadingState.success(res['data']);
+    } else {
+      return const Error('');
+    }
+  }
+}