Add duplicate option for non-OOTB custom serving runtimes

[DaoDaoNoCode]

Closes #1499

Description

Simply add a dropdown option.

Now for OOTB custom serving runtimes:

For non-OOTB custom serving runtimes:

How Has This Been Tested?

1. Import a new custom serving runtime or duplicate an OOTB serving runtime, to make a non-OOTB serving runtime
2. Check the dropdown menu of the new custom serving runtime
3. You should be able to duplicate the non-OOTB serving runtime now

Test Impact

N/A

Request review criteria:

Self checklist (all need to be checked):

• The developer has manually tested the changes and verified that the changes work
• Commits have been squashed into descriptive, self-contained units of work (e.g. 'WIP' and 'Implements feedback' style messages have been removed)
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has added tests or explained why testing cannot be added (unit tests & storybook for related changes)

If you have UI changes:

• Included any necessary screenshots or gifs if it was a UI change.
• Included tags to the UX team if it was a UI/UX change (find relevant UX in the SMEs section).

After the PR is posted & before it merges:

• The developer has tested their solution on a cluster by using the image produced by the PR to main

[DaoDaoNoCode]

@vconzola Could you check the visual changes?

[vconzola]

@DaoDaoNoCode Can you take a screenshot of the Duplicate modal? I want to see what you're using for the modal heading and the runtime name. @kaedward is looking into inconsistencies in the current UI in similar modals and we might as well do it right the first time in this one.

[DaoDaoNoCode]

@vconzola It's not going to a modal, it will go to a new page with the preset YAML code.

[lucferbux]

btw @vconzola we have #1727 to fix the inconsistency of "Add" instead "Duplicate" I'm gonna take that to see if we can fix it asap

[lucferbux]

/lgtm

Not approving until UX gives the lgtm too, I've added another comment to track the inconsistency we have right now for the "Duplicate" page.

[vconzola]

The dropdown change lgtm.

I'll add a comment to #1727 re: the wording changes.

[manaswinidas]

/lgtm

Tested. Works fine.

[lucferbux]

/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lucferbux, manaswinidas

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