Update genscenario command to use gardener api submodule

[takoverflow]

What this PR does / why we need it:
This PR updates the genscenario gardener subcommand to:

1. Use gardener apis submodule rather than unstructured
2. Fix the obfuscation logic to properly account for selectors, affinities etc
3. Use shoot and the cloudprofile resources to construct the required data rather than relying on control plane worker resource.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Release note:

[gardener-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment