Add annotation that triggers a volume recreation

[maboehm]

How to categorize this PR?
/kind enhancement

What this PR does / why we need it:
Adds a new annotationdruid.gardener.cloud/recreate-volumes that triggers a recreation of all PVCs.
Details are documented in recreate-volumes.md

Which issue(s) this PR fixes:
ADO#628815

Special notes for your reviewer:
I tried to keep the changes to existing files / functions minimal. Main injection points are:

• setting annotations in the main reconcile() function (+ an additional check)
• optionally adding a task to delete all old PVCs
• setting the template.Annotations accordingly

You can check a running version of the change on ond-bba32c

[maboehm]

I don't understand why etcd-events behaves that way. But since we wont be recreating it (it does not use gardener.cloud-fast storage class), I think its fine. I added validation to only allow volume recreation on etcds that have backups enabled.

[maboehm]

/test pull-etcd-druid-images-dev

[maboehm]

I think I fixed the flake, the second PVC now has the suffix -1 and PVCs should be cleaned up correctly

[ske-prow]

LGTM label has been added.

Git tree hash: 5939e74c88a2cbdb8792ab68b8608bbb723edc1f

[ske-prow]

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