Get thumbnail from app (#68)

* Renamed multipart filed name 'files' to 'assetData'. 
* Added an additional field name of 'thumbnailData' to multipart form.
* Implemented upload mechanism for thumbnail directly from the mobile client.
* Removed dead code
* Implemented a version checking mechanism.

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

@@ -0,0 +1,78 @@
+import 'dart:convert';
+
+import 'package:immich_mobile/shared/models/mapbox_info.model.dart';
+import 'package:immich_mobile/shared/models/server_version.model.dart';
+
+class ServerInfoState {
+  final MapboxInfo mapboxInfo;
+  final ServerVersion serverVersion;
+  final bool isVersionMismatch;
+  final String versionMismatchErrorMessage;
+
+  ServerInfoState({
+    required this.mapboxInfo,
+    required this.serverVersion,
+    required this.isVersionMismatch,
+    required this.versionMismatchErrorMessage,
+  });
+
+  ServerInfoState copyWith({
+    MapboxInfo? mapboxInfo,
+    ServerVersion? serverVersion,
+    bool? isVersionMismatch,
+    String? versionMismatchErrorMessage,
+  }) {
+    return ServerInfoState(
+      mapboxInfo: mapboxInfo ?? this.mapboxInfo,
+      serverVersion: serverVersion ?? this.serverVersion,
+      isVersionMismatch: isVersionMismatch ?? this.isVersionMismatch,
+      versionMismatchErrorMessage: versionMismatchErrorMessage ?? this.versionMismatchErrorMessage,
+    );
+  }
+
+  Map<String, dynamic> toMap() {
+    return {
+      'mapboxInfo': mapboxInfo.toMap(),
+      'serverVersion': serverVersion.toMap(),
+      'isVersionMismatch': isVersionMismatch,
+      'versionMismatchErrorMessage': versionMismatchErrorMessage,
+    };
+  }
+
+  factory ServerInfoState.fromMap(Map<String, dynamic> map) {
+    return ServerInfoState(
+      mapboxInfo: MapboxInfo.fromMap(map['mapboxInfo']),
+      serverVersion: ServerVersion.fromMap(map['serverVersion']),
+      isVersionMismatch: map['isVersionMismatch'] ?? false,
+      versionMismatchErrorMessage: map['versionMismatchErrorMessage'] ?? '',
+    );
+  }
+
+  String toJson() => json.encode(toMap());
+
+  factory ServerInfoState.fromJson(String source) => ServerInfoState.fromMap(json.decode(source));
+
+  @override
+  String toString() {
+    return 'ServerInfoState(mapboxInfo: $mapboxInfo, serverVersion: $serverVersion, isVersionMismatch: $isVersionMismatch, versionMismatchErrorMessage: $versionMismatchErrorMessage)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+
+    return other is ServerInfoState &&
+        other.mapboxInfo == mapboxInfo &&
+        other.serverVersion == serverVersion &&
+        other.isVersionMismatch == isVersionMismatch &&
+        other.versionMismatchErrorMessage == versionMismatchErrorMessage;
+  }
+
+  @override
+  int get hashCode {
+    return mapboxInfo.hashCode ^
+        serverVersion.hashCode ^
+        isVersionMismatch.hashCode ^
+        versionMismatchErrorMessage.hashCode;
+  }
+}