Add: Support for specifying elliptic curves in TLS handshake

[richardsonnick]

To support new option set default ssl curves.
Adds an option to TLSProfile config to add a list of supported groups.

See for more context openshift/cluster-ingress-operator#1287

[openshift-ci]

Hello @richardsonnick! 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.

[everettraven]

/assign

[everettraven]

Have a handful of comments.

Additionally, this is a change to a v1 API and requires that the new field is introduced behind a new feature gate.

That means there will need to be an enhancement proposal written that includes how components are expected to behave with this change, changes that need to be made, and a plan for how the changes will be tested.

[openshift-ci]

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[richardsonnick]

Additionally, this is a change to a v1 API and requires that the new field is introduced behind a new feature gate.

Sorry for the over sight on this, first time contributing. I'll circle back with a more in depths review of this change.

[openshift-ci]

@richardsonnick: 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/verify	93fe07b	link	true	/test verify
ci/prow/lint	93fe07b	link	true	/test lint

Full PR test history. Your PR dashboard.

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