feat(backend): support separate artifact repository per namespace. Fixes #4649

[arllanos]

Description of your changes:

Support configuring separate artifact repository for each namespace.

• Modify backend methods that submits Pipelines Runs, so that artifactRepositoryRef field is injected in the Argo workflow spec before workflow is submitted to the K8s API

Note: as mentioned in the linked issue #4649 this feature depends on upgrading Argo to version 2.9 or later

/cc @Bobgy

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: arllanos
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[k8s-ci-robot]

Hi @arllanos. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[arllanos]

@googlebot I signed it!

[arllanos]

Closing this PR. This will be re-done in the pwc-labs github organization.