fix(server): use correct file extension for motion photo videos (#8659)

* fix(server): use mp4 file extension for motion photo videos in archive download

* always use mp4 for videos

* get file extension from originalPath

* remove console log

* store motion assets with mp4 extension

* add migration

* set originalFileName for live photo asset stubs

* leave down migration empty

* only set originalFileName for livePhotoStillAsset

* use separate stub

* shorter stub name

server/test/fixtures/asset.stub.ts

@@ -486,6 +486,22 @@ export const assetStub = {
     },
   } as AssetEntity),
 
+  livePhotoWithOriginalFileName: Object.freeze({
+    id: 'live-photo-still-asset',
+    originalPath: fileStub.livePhotoStill.originalPath,
+    originalFileName: fileStub.livePhotoStill.originalName,
+    ownerId: authStub.user1.user.id,
+    type: AssetType.IMAGE,
+    livePhotoVideoId: 'live-photo-motion-asset123',
+    isVisible: true,
+    fileModifiedAt: new Date('2022-06-19T23:41:36.910Z'),
+    fileCreatedAt: new Date('2022-06-19T23:41:36.910Z'),
+    exifInfo: {
+      fileSizeInByte: 25_000,
+      timeZone: `America/New_York`,
+    },
+  } as AssetEntity),
+
   withLocation: Object.freeze<AssetEntity>({
     id: 'asset-with-favorite-id',
     deviceAssetId: 'device-asset-id',