* Refactor labl api
move to the new program model
Signed-off-by: wang yan <wangyan@vmware.com>
* continue resolve review comments
Signed-off-by: Wang Yan <wangyan@vmware.com>
This commit add supporting for adding/removing label to/from artifacts and populates labels when listing artifacts
Signed-off-by: Wenkai Yin <yinw@vmware.com>