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

server/src/api-v1/asset/dto/update-exif.dto.ts

@@ -0,0 +1,4 @@
+import { PartialType } from '@nestjs/mapped-types';
+import { CreateExifDto } from './create-exif.dto';
+
+export class UpdateExifDto extends PartialType(CreateExifDto) {}