feat(server): improve thumbnail relation and updating (#1897)

* feat(server): improve thumbnail relation and updating

* improve query + update tests and migration

* make sure uuids are valid in migration

* fix unit test

server/libs/domain/test/fixtures.ts

@@ -163,6 +163,7 @@ export const albumStub = {
     ownerId: authStub.admin.id,
     owner: userEntityStub.admin,
     assets: [],
+    albumThumbnailAsset: null,
     albumThumbnailAssetId: null,
     createdAt: new Date().toISOString(),
     updatedAt: new Date().toISOString(),
@@ -422,6 +423,7 @@ export const sharedLinkStub = {
       albumName: 'Test Album',
       createdAt: today.toISOString(),
       updatedAt: today.toISOString(),
+      albumThumbnailAsset: null,
       albumThumbnailAssetId: null,
       sharedUsers: [],
       sharedLinks: [],