Edit Knative domain after it has been deployed

What does this MR do?

This MR adds the ability to edit Knative domain after it has been deployed.

What are the relevant issue numbers?

Closes #56937 (closed)

Successful update

Update failure

To simulate an "Update failure", the following commands can be executed:

Open rails console: bundle exec rails console

In rails console execute the following:

1. cluster = Clusters::Cluster.find <id> Note: <id> can be found in the browser url when navigating to the cluster
2. knative = cluster.application_knative
3. knative.update!(status: 6)

The runner on the specified cluster should now be in the update_errored state, and should display the Retry upgrade button

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides