CFE-1168: Add CMPSMachineNamePrefix feature-gate

[chiragkyal]

Add new CMPSMachineNamePrefix feature-gate to guard the implementation changes done to support customized control plane machine names.

• Part of CFE-1168
• Implements https://github.com/openshift/enhancements/pull/1714

[openshift-ci-robot]

@chiragkyal: This pull request references CFE-1168 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "4.18.0" version, but no target version was set.

In response to [this](https://github.com/openshift/api/pull/2094): >Add new `CMPSMachineNamePrefix` feature-gate to guard the implementation changes done to support customized control plane machine names. > >- Part of [CFE-1168](https://issues.redhat.com/browse/CFE-1168) >- Implements https://github.com/openshift/enhancements/pull/1714 Instructions for interacting with me using PR comments are available [here](https://prow.ci.openshift.org/command-help?repo=openshift%2Fapi). If you have questions or suggestions related to my behavior, please file an issue against the [openshift-eng/jira-lifecycle-plugin](https://github.com/openshift-eng/jira-lifecycle-plugin/issues/new) repository.

[openshift-ci[bot]]

Hello @chiragkyal! Some important instructions when contributing to openshift/api: API design plays an important part in the user experience of OpenShift and as such API PRs are subject to a high level of scrutiny to ensure they follow our best practices. If you haven't already done so, please review the OpenShift API Conventions and ensure that your proposed changes are compliant. Following these conventions will help expedite the api review process for your PR.

[chiragkyal]

/assign @JoelSpeed

[chiragkyal]

/test e2e-aws-serial-techpreview

[openshift-ci[bot]]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: chiragkyal Once this PR has been reviewed and has the lgtm label, please ask for approval from joelspeed. For more information see the Kubernetes Code Review Process.

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[openshift-ci[bot]]

@chiragkyal: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-aws-ovn-techpreview	d20e11f92402e2cec838e53a110de0cf1f24b5fd	link	true	/test e2e-aws-ovn-techpreview
ci/prow/e2e-aws-ovn	d20e11f92402e2cec838e53a110de0cf1f24b5fd	link	true	/test e2e-aws-ovn
ci/prow/okd-scos-e2e-aws-ovn	d20e11f92402e2cec838e53a110de0cf1f24b5fd	link	false	/test okd-scos-e2e-aws-ovn

Full PR test history. Your PR dashboard.

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