Problem Description: 
Right now when clicking the `sign` button on the EE UI, it signs all the tags on the image, if there are 10 tags, it will create 10 signatures for each tag 

In a huge repo it will take some time.

Proposed Solution:

UI have to pass `tags_list` parameter to the `/sign` endpoint and feed that based on user selection from a checkbox listing all the tags. 

Pulp container API exposes the tags for an image

Add some feedback in the UI that indicates whether a specific tag has been signed. We will need to verify with API team if we have an endpoint that will fetch this information.

Reminders:

• Set the affected Component(s): Backend, Infrastructure, Pulp, QE, Security, UI
• Apply labels "crc-automation-hub" and/or "private-automation-hub" to indicate if the issue is for Cloud Automation Hub, Private Automation Hub, or both