[release-0.9] ✨ support server group and scheduler hint additional properties

[okozachenko1203]

What this PR does / why we need it:
This PR adds a new field SchedulerHintAdditionalProperties in both OpenstackServerSpec and OpenstackMachineSpec to specify nova scheduler hint properties during server creation.
In addition, it passes openStackMachineSpec.ServerGroup to OpenStackServerSpec.ServerGroup which seems missing during the spec conversion.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

1. Please confirm that if this PR changes any image versions, then that's the sole change this PR makes.

TODOs:

• squashed commits
• if necessary:
  • includes documentation
  • adds unit tests

/hold

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @okozachenko1203. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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.

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[EmilienM]

/ok-to-test