Refactor codebase resolving warnings and remove self-package imports

lib/api/marianumcloud/talk/sendMessage/sendMessage.dart

@@ -1,9 +1,9 @@
 import 'package:http/http.dart' as http;
-import 'package:http/src/response.dart';
-import 'package:marianum_mobile/api/marianumcloud/talk/sendMessage/sendMessageParams.dart';
-import 'package:marianum_mobile/api/marianumcloud/talk/talkApi.dart';
+import 'package:http/http.dart';
 
 import '../../../apiParams.dart';
+import '../talkApi.dart';
+import 'sendMessageParams.dart';
 
 class SendMessage extends TalkApi {
   String chatToken;

lib/api/marianumcloud/talk/sendMessage/sendMessageParams.dart

@@ -1,5 +1,6 @@
 import 'package:json_annotation/json_annotation.dart';
-import 'package:marianum_mobile/api/apiParams.dart';
+
+import '../../../apiParams.dart';
 
 part 'sendMessageParams.g.dart';
 

lib/api/marianumcloud/talk/sendMessage/sendMessageResponse.dart

@@ -1,4 +1,4 @@
-import 'package:marianum_mobile/api/apiResponse.dart';
+import '../../../apiResponse.dart';
 
 class SendMessageResponse extends ApiResponse {