Experimental support for IPv6

[mluk-sap]

Description

Changes proposed in this pull request:

• Added experimental Dual Stack support
• Changed 'experimental' features usage detection -> it now causes error and breaks the reconciliation
• Added support for creating EnvoyFilter for Proxy Protocol if cluster if NLB and dual stack

Pre-Merge Checklist

Consider all the following items. If your contribution violates any of them, or you are not sure about it, add a comment to the PR.

• The code coverage is acceptable.
• Release notes for the introduced changes are created.
• If Kubebuilder changes were made, you ran make generate-manifests and committed the changes before the merge.
• Pre-existing managed resources are correctly handled.
• The change works on all hyperscalers supported by SAP BTP, Kyma runtime.
  (was tested on AWS and GCP, because only these support dual stack)
• There is no upgrade downtime.
  (it requires a new infrastructure that supports dual stack, migrations are also not well supported, it is an experimental feature that enables testing)
• For infrastructure changes, you checked if the changes affect the hyperscaler's costs.
  (experimental feature, it was not checked)
• RBAC settings are as restrictive as possible.
• If any new libraries are added, you verified license compliance and maintainability, and made a comment in the PR with details. We only allow stable releases to be included in the project.
  (no libraries)
• You checked if this change should be cherry-picked to active release branches.
  (should be)
• The configuration does not introduce any additional latency.

Related issues

[mluk-sap]

IOP changes for IPv6:

mesh config dual stack
spec.meshConfig.defaultConfig.proxyMetadata.ISTIO_DUAL_STACK = "true"

pilot env dual stack
spec.values.pilot.env.ISTIO_DUAL_STACK = "true"

pilot ipfamilypolicy
spec.values.pilot.ipFamilyPolicy RequireDualStack

ingress ipfamilypolicy
spec.values.gateways.istio-ingressgateway.ipFamilyPolicy = RequireDualStack

egress ipfamilypolicy
spec.values.gateways.istio-egressgateway.ipFamilyPolicy = RequireDualStack