label multiple artifacts at once

[phin1x]

Is your feature request related to a problem? Please describe.
in the current versions of harbor (v2.1.3 and v2.2.0) you only can add one label to one artifact in the web ui. The "Add Labels" menu under "Actions" is grayed out if you select multiple artifacts. This is very annoying if you want to label multiple artifacts or all artifacts from a repository.

Describe the solution you'd like
Allow to add multiple labels to multiple artifacts at once in the web ui.

Describe the main design/architecture of your solution

Describe the development plan you've considered

Additional context