118 - Implement shared album feature (#124)

* New features 
  - Share album. Users can now create albums to share with existing people on the network.
  - Owner can delete the album.
  - Owner can invite the additional users to the album.
  - Shared users and the owner can add additional assets to the album.
* In the asset viewer, the user can swipe up to see detailed information and swip down to dismiss.
* Several UI enhancements.

mobile/lib/modules/sharing/models/shared_user.model.dart

@@ -0,0 +1,76 @@
+import 'dart:convert';
+
+import 'package:immich_mobile/shared/models/user_info.model.dart';
+
+class SharedUsers {
+  final int id;
+  final String albumId;
+  final String sharedUserId;
+  final UserInfo userInfo;
+
+  SharedUsers({
+    required this.id,
+    required this.albumId,
+    required this.sharedUserId,
+    required this.userInfo,
+  });
+
+  SharedUsers copyWith({
+    int? id,
+    String? albumId,
+    String? sharedUserId,
+    UserInfo? userInfo,
+  }) {
+    return SharedUsers(
+      id: id ?? this.id,
+      albumId: albumId ?? this.albumId,
+      sharedUserId: sharedUserId ?? this.sharedUserId,
+      userInfo: userInfo ?? this.userInfo,
+    );
+  }
+
+  Map<String, dynamic> toMap() {
+    final result = <String, dynamic>{};
+
+    result.addAll({'id': id});
+    result.addAll({'albumId': albumId});
+    result.addAll({'sharedUserId': sharedUserId});
+    result.addAll({'userInfo': userInfo.toMap()});
+
+    return result;
+  }
+
+  factory SharedUsers.fromMap(Map<String, dynamic> map) {
+    return SharedUsers(
+      id: map['id']?.toInt() ?? 0,
+      albumId: map['albumId'] ?? '',
+      sharedUserId: map['sharedUserId'] ?? '',
+      userInfo: UserInfo.fromMap(map['userInfo']),
+    );
+  }
+
+  String toJson() => json.encode(toMap());
+
+  factory SharedUsers.fromJson(String source) => SharedUsers.fromMap(json.decode(source));
+
+  @override
+  String toString() {
+    return 'SharedUsers(id: $id, albumId: $albumId, sharedUserId: $sharedUserId, userInfo: $userInfo)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+
+    return other is SharedUsers &&
+        other.id == id &&
+        other.albumId == albumId &&
+        other.sharedUserId == sharedUserId &&
+        other.userInfo == userInfo;
+  }
+
+  @override
+  int get hashCode {
+    return id.hashCode ^ albumId.hashCode ^ sharedUserId.hashCode ^ userInfo.hashCode;
+  }
+}