Add customLabels to ServiceInstance and ServiceBinding

[kaedwen]

Pull Request Template

Prerequisites

fixes #453

Motivation

We are using the btp-service-operator in our environment and we need to create hana-shared aka. hana tenants. During this to also be consumable via CAP there must be a label for tenant_id and service_plan_id because CAP searches for it.

To be able to provide that from a kubernetes environment the solution would be to allow adding custom labels to the CRD's.

Approach

With that PR the CRD's have an additional customLabels field where labels can be added to the instance/binding

Pull Request status

• Initial implementation
• Refactoring
• Unit tests
• Integration tests

Third-party code

none