feat: add search_column parameter and search_columns response field for targeted search (#207)

src/fastapi_toolsets/schemas.py

@@ -162,6 +162,7 @@ class PaginatedResponse(BaseResponse, Generic[DataT]):
     pagination: OffsetPagination | CursorPagination
     pagination_type: PaginationType | None = None
     filter_attributes: dict[str, list[Any]] | None = None
+    search_columns: list[str] | None = None
 
     _discriminated_union_cache: ClassVar[dict[Any, Any]] = {}