Add opt to use AZ for APISeverLoadBalancer

[dulek]

What this PR does / why we need it:
Add option to provide AZ for apiserver LB.

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

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[dulek]

This is fixing #1979.

[mdbooth]

I've approved, but please add the 2 new restorers to their respective fuzz testers before merging. Thanks!

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mdbooth

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[mdbooth]

Let's get this in.

/hold cancel
/lgtm