Implemented EXIF store and display (#19)

* Added EXIF extracting in the backend
* Added EXIF displaying on `image_viewer_page.dart`
* Added Icon for backup option not enable

mobile/lib/shared/models/immich_asset_with_exif.model.dart

@@ -0,0 +1,133 @@
+import 'dart:convert';
+
+import 'package:immich_mobile/shared/models/exif.model.dart';
+
+class ImmichAssetWithExif {
+  final String id;
+  final String deviceAssetId;
+  final String userId;
+  final String deviceId;
+  final String type;
+  final String createdAt;
+  final String modifiedAt;
+  final String originalPath;
+  final bool isFavorite;
+  final String? duration;
+  final ImmichExif? exifInfo;
+
+  ImmichAssetWithExif({
+    required this.id,
+    required this.deviceAssetId,
+    required this.userId,
+    required this.deviceId,
+    required this.type,
+    required this.createdAt,
+    required this.modifiedAt,
+    required this.originalPath,
+    required this.isFavorite,
+    this.duration,
+    this.exifInfo,
+  });
+
+  ImmichAssetWithExif copyWith({
+    String? id,
+    String? deviceAssetId,
+    String? userId,
+    String? deviceId,
+    String? type,
+    String? createdAt,
+    String? modifiedAt,
+    String? originalPath,
+    bool? isFavorite,
+    String? duration,
+    ImmichExif? exifInfo,
+  }) {
+    return ImmichAssetWithExif(
+      id: id ?? this.id,
+      deviceAssetId: deviceAssetId ?? this.deviceAssetId,
+      userId: userId ?? this.userId,
+      deviceId: deviceId ?? this.deviceId,
+      type: type ?? this.type,
+      createdAt: createdAt ?? this.createdAt,
+      modifiedAt: modifiedAt ?? this.modifiedAt,
+      originalPath: originalPath ?? this.originalPath,
+      isFavorite: isFavorite ?? this.isFavorite,
+      duration: duration ?? this.duration,
+      exifInfo: exifInfo ?? this.exifInfo,
+    );
+  }
+
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'deviceAssetId': deviceAssetId,
+      'userId': userId,
+      'deviceId': deviceId,
+      'type': type,
+      'createdAt': createdAt,
+      'modifiedAt': modifiedAt,
+      'originalPath': originalPath,
+      'isFavorite': isFavorite,
+      'duration': duration,
+      'exifInfo': exifInfo?.toMap(),
+    };
+  }
+
+  factory ImmichAssetWithExif.fromMap(Map<String, dynamic> map) {
+    return ImmichAssetWithExif(
+      id: map['id'] ?? '',
+      deviceAssetId: map['deviceAssetId'] ?? '',
+      userId: map['userId'] ?? '',
+      deviceId: map['deviceId'] ?? '',
+      type: map['type'] ?? '',
+      createdAt: map['createdAt'] ?? '',
+      modifiedAt: map['modifiedAt'] ?? '',
+      originalPath: map['originalPath'] ?? '',
+      isFavorite: map['isFavorite'] ?? false,
+      duration: map['duration'],
+      exifInfo: map['exifInfo'] != null ? ImmichExif.fromMap(map['exifInfo']) : null,
+    );
+  }
+
+  String toJson() => json.encode(toMap());
+
+  factory ImmichAssetWithExif.fromJson(String source) => ImmichAssetWithExif.fromMap(json.decode(source));
+
+  @override
+  String toString() {
+    return 'ImmichAssetWithExif(id: $id, deviceAssetId: $deviceAssetId, userId: $userId, deviceId: $deviceId, type: $type, createdAt: $createdAt, modifiedAt: $modifiedAt, originalPath: $originalPath, isFavorite: $isFavorite, duration: $duration, exifInfo: $exifInfo)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+
+    return other is ImmichAssetWithExif &&
+        other.id == id &&
+        other.deviceAssetId == deviceAssetId &&
+        other.userId == userId &&
+        other.deviceId == deviceId &&
+        other.type == type &&
+        other.createdAt == createdAt &&
+        other.modifiedAt == modifiedAt &&
+        other.originalPath == originalPath &&
+        other.isFavorite == isFavorite &&
+        other.duration == duration &&
+        other.exifInfo == exifInfo;
+  }
+
+  @override
+  int get hashCode {
+    return id.hashCode ^
+        deviceAssetId.hashCode ^
+        userId.hashCode ^
+        deviceId.hashCode ^
+        type.hashCode ^
+        createdAt.hashCode ^
+        modifiedAt.hashCode ^
+        originalPath.hashCode ^
+        isFavorite.hashCode ^
+        duration.hashCode ^
+        exifInfo.hashCode;
+  }
+}