Improve UX of registering a GitLab Agent

Problem to solve

After a user has created an Agent (Define a configuration repository) by creating a configuration file and returned to the Kubernetes clusters screen, to proceed they must register an agent. Currently, the options to trigger that action are clicking the Install new agent button, clicking the Action button, or selecting the Connect with agent dropdown action. This interaction has the following problems:

• The button labels do not match the action they will be performing
• User has previously clicked these buttons to perform a different action and must know the actions have changed (low discoverability)
• There is no feedback that the creation was successful
• If a user wanted to create a second agent, they are prevented from doing that until they have registered the first.
• There is a scenario where a user adds multiple agents at the same time, but if they complete the registration of one, there is no way to register the subsequent Agents.

Proposal

Add another tab to the table for available configurations (this tab is hidden when there are no available configurations):

Design