Enrich Runtime CRs with commercial service plan data

[a-thaler]

Description
In order to migrate KMC to leverage runtime CRs only (kyma-project/kyma-metrics-collector#89) and get rid of the KEB to EDP call (kyma-project/kyma-metrics-collector#90), KMC need to have access to the commercial service plan data of a runtime/subacount.

Goal: Enrich every runtime CR with the service plan information of the underlying subscription

Every subscription belongs to a service plan like "standard", "test", or "tdd".

[PK85]

@a-thaler I think this mapping from KEB could be moved to KMC and then we do not add more labels to the RuntimeCR, see:

kyma-environment-broker/internal/process/provisioning/edp_registration.go

Line 134 in 186190e

func (s *EDPRegistrationStep) selectServicePlan(planID string) string {

[a-thaler]

I agree, the mapping should be moved to KMC indeed, will close the ticket