fix: http/https proxy (#7821)

* add http(s) proxy

* Add front-end translation

* fix ui description

* For linux platform, add rustls support

* fix: Fix the proxy address test function.

* add: Added default prompts for agency agreement and some multi-language translations

* add: Http proxy request client

* fix: add async http proxy func and format the code

* add: Preliminary support for flutter front-end calling rust back-end http request

* Optimize HTTP calls

* Optimize HTTP calls

* fix: Optimize HTTP requests, refine translations, and fix dependencies

* fix: Win and macOS compilation errors

* fix: web platforms

* fix: Optimize import

* fix: Fix web platform issues

* fix: Fix web platform issues

* fix: update ci

* fix: test ci

* test: test CI

* Revert "fix: update ci"

This reverts commit 2e5f247b2e.

* test: test CI

* test: test CI

* fix: fix lock file

* fix: Optimize imports

flutter/lib/models/ab_model.dart

@@ -10,8 +10,8 @@ import 'package:flutter_hbb/models/peer_model.dart';
 import 'package:flutter_hbb/models/platform_model.dart';
 import 'package:get/get.dart';
 import 'package:bot_toast/bot_toast.dart';
-import 'package:http/http.dart' as http;
 
+import '../utils/http_service.dart' as http;
 import '../common.dart';
 
 final syncAbOption = 'sync-ab-with-recent-sessions';

flutter/lib/models/group_model.dart

@@ -7,7 +7,7 @@ import 'package:flutter_hbb/models/peer_model.dart';
 import 'package:flutter_hbb/models/platform_model.dart';
 import 'package:get/get.dart';
 import 'dart:convert';
-import 'package:http/http.dart' as http;
+import '../utils/http_service.dart' as http;
 
 class GroupModel {
   final RxBool groupLoading = false.obs;

flutter/lib/models/user_model.dart

@@ -6,9 +6,9 @@ import 'package:flutter/material.dart';
 import 'package:flutter_hbb/common/hbbs/hbbs.dart';
 import 'package:flutter_hbb/models/ab_model.dart';
 import 'package:get/get.dart';
-import 'package:http/http.dart' as http;
 
 import '../common.dart';
+import '../utils/http_service.dart' as http;
 import 'model.dart';
 import 'platform_model.dart';
 
@@ -136,7 +136,6 @@ class UserModel {
   Future<LoginResponse> login(LoginRequest loginRequest) async {
     final url = await bind.mainGetApiServer();
     final resp = await http.post(Uri.parse('$url/api/login'),
-        headers: {'Content-Type': 'application/json'},
         body: jsonEncode(loginRequest.toJson()));
 
     final Map<String, dynamic> body;