Refactored DI, serialization, added feedback to document download

lib/features/login/model/authentication_information.dart

@@ -2,30 +2,22 @@ import 'package:paperless_mobile/core/type/types.dart';
 import 'package:paperless_mobile/features/login/model/client_certificate.dart';
 
 class AuthenticationInformation {
-  static const usernameKey = 'username';
-  static const passwordKey = 'password';
   static const tokenKey = 'token';
   static const serverUrlKey = 'serverUrl';
   static const clientCertificateKey = 'clientCertificate';
 
-  final String username;
-  final String password;
-  final String token;
+  final String? token;
   final String serverUrl;
   final ClientCertificate? clientCertificate;
 
   AuthenticationInformation({
-    required this.username,
-    required this.password,
-    required this.token,
+    this.token,
     required this.serverUrl,
     this.clientCertificate,
   });
 
   AuthenticationInformation.fromJson(JSON json)
-      : username = json[usernameKey],
-        password = json[passwordKey],
-        token = json[tokenKey],
+      : token = json[tokenKey],
         serverUrl = json[serverUrlKey],
         clientCertificate = json[clientCertificateKey] != null
             ? ClientCertificate.fromJson(json[clientCertificateKey])
@@ -33,8 +25,6 @@ class AuthenticationInformation {
 
   JSON toJson() {
     return {
-      usernameKey: username,
-      passwordKey: password,
       tokenKey: token,
       serverUrlKey: serverUrl,
       clientCertificateKey: clientCertificate?.toJson(),
@@ -42,21 +32,16 @@ class AuthenticationInformation {
   }
 
   bool get isValid {
-    return serverUrl.isNotEmpty && token.isNotEmpty;
+    return serverUrl.isNotEmpty && (token?.isNotEmpty ?? false);
   }
 
   AuthenticationInformation copyWith({
-    String? username,
-    String? password,
     String? token,
     String? serverUrl,
     ClientCertificate? clientCertificate,
     bool removeClientCertificate = false,
-    bool? isLocalAuthenticationEnabled,
   }) {
     return AuthenticationInformation(
-      username: username ?? this.username,
-      password: password ?? this.password,
       token: token ?? this.token,
       serverUrl: serverUrl ?? this.serverUrl,
       clientCertificate: clientCertificate ??