use a separate table instead of a column on remote asset

mobile/lib/infrastructure/entities/remote_asset.entity.dart

@@ -19,7 +19,6 @@ ON remote_asset_entity (owner_id, library_id, checksum)
 WHERE (library_id IS NOT NULL);
 ''')
 @TableIndex.sql('CREATE INDEX IF NOT EXISTS idx_remote_asset_checksum ON remote_asset_entity (checksum)')
-@TableIndex.sql('CREATE INDEX IF NOT EXISTS idx_remote_asset_cloud_id ON remote_asset_entity (cloud_id);')
 class RemoteAssetEntity extends Table with DriftDefaultsMixin, AssetEntityMixin {
   const RemoteAssetEntity();
 
@@ -45,8 +44,6 @@ class RemoteAssetEntity extends Table with DriftDefaultsMixin, AssetEntityMixin
 
   TextColumn get libraryId => text().nullable()();
 
-  TextColumn get cloudId => text().nullable()();
-
   @override
   Set<Column> get primaryKey => {id};
 }