Adapt high-availability configuration

[timuthy]

How to categorize this PR?

/area high-availability
/area networking
/kind enhancement

What this PR does / why we need it:
This PR prepares components for HA by labeling them with the corresponding high-availability-config.resources.gardener.cloud/type and defining the required PodDisruptionBudget, please see this document for more information.

Which issue(s) this PR fixes:
Part of gardener/gardener#6529

Special notes for your reviewer:

• Hubble is excluded from any HA handling to follow the observability guideline (see this section)
• Cilium-Etcd-Operator is not prepared for any HA setup, it doesn't support leader election
• Preflight is also not touched as I couldn't verify it at runtime (can it even be activated?)

Release note:

Extension and control-plane components have been adjusted to the high availability configuration supported by Gardener as of release `v1.60`. See [this document](https://github.com/gardener/gardener/blob/master/docs/development/high-availability.md) for more information about HA in gardener.

This release adds HA support for Ciliums's operator when extension is deployed along with Gardener >= `v1.60`. Please see [this document](https://github.com/gardener/gardener/blob/master/docs/usage/shoot_high_availability.md) for more information about HA settings in shoot clusters.

[ScheererJ]

Please rebase.

[timuthy]

Thanks @ScheererJ, PTAL.

[ScheererJ]

/lgtm