Share assets from mobile to other apps (#435)

* Share unique assets

* Style share preparing dialog

* Share assets from multiselect

* Fix i18n

* Use navigator like in delete dialog

* Center bottom-bar buttons

mobile/lib/shared/services/share.service.dart

@@ -0,0 +1,45 @@
+
+import 'dart:io';
+
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:immich_mobile/shared/providers/api.provider.dart';
+import 'package:openapi/api.dart';
+import 'package:path_provider/path_provider.dart';
+import 'package:share_plus/share_plus.dart';
+import 'package:path/path.dart' as p;
+import 'api.service.dart';
+
+final shareServiceProvider =
+  Provider((ref) => ShareService(ref.watch(apiServiceProvider)));
+
+class ShareService {
+  final ApiService _apiService;
+
+  ShareService(this._apiService);
+
+  Future<void> shareAsset(AssetResponseDto asset) async {
+    await shareAssets([asset]);
+  }
+
+  Future<void> shareAssets(List<AssetResponseDto> assets) async {
+    final downloadedFilePaths = assets.map((asset) async {
+      final res = await _apiService.assetApi.downloadFileWithHttpInfo(
+        asset.deviceAssetId,
+        asset.deviceId,
+        isThumb: false,
+        isWeb: false,
+      );
+
+      final fileName = p.basename(asset.originalPath);
+
+      final tempDir = await getTemporaryDirectory();
+      final tempFile = await File('${tempDir.path}/$fileName').create();
+      tempFile.writeAsBytesSync(res.bodyBytes);
+
+      return tempFile.path;
+    });
+
+    Share.shareFiles(await Future.wait(downloadedFilePaths));
+  }
+
+}