refactor(mobile): device asset entity to use modified time (#17064)

* refactor: device asset entity to use modified time

* chore: cleanup

* refactor: remove album media dependency from hashservice

* refactor: return updated copy of asset

* add hash service tests

* chore: rename hash batch constants

* chore: log the number of assets processed during migration

* chore: more logs

* refactor: use lookup and more tests

* use sort approach

* refactor hash service to use for loop instead

* refactor: rename to getByIds

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>

mobile/test/fixtures/asset.stub.dart

@@ -8,8 +8,8 @@ final class AssetStub {
     localId: "image1",
     remoteId: 'image1-remote',
     ownerId: 1,
-    fileCreatedAt: DateTime.now(),
-    fileModifiedAt: DateTime.now(),
+    fileCreatedAt: DateTime(2019),
+    fileModifiedAt: DateTime(2020),
     updatedAt: DateTime.now(),
     durationInSeconds: 0,
     type: AssetType.image,
@@ -34,4 +34,19 @@ final class AssetStub {
     isArchived: false,
     isTrashed: false,
   );
+
+  static final image3 = Asset(
+    checksum: "image3-checksum",
+    localId: "image3",
+    ownerId: 1,
+    fileCreatedAt: DateTime(2025),
+    fileModifiedAt: DateTime(2025),
+    updatedAt: DateTime.now(),
+    durationInSeconds: 60,
+    type: AssetType.image,
+    fileName: "image3.jpg",
+    isFavorite: true,
+    isArchived: false,
+    isTrashed: false,
+  );
 }