BTP Kyma EU access implementation - register cf-ch20 region and drop whitelisting

[PK85]

Main ticket: https://github.tools.sap/kyma/backlog/issues/3115

AC

• [ ] 1) KEB service catalog schema is registered in CIS and ERS in cf-ch20
• [x] 2) Drop support for EU access allow list in KEB (if someone enables Kyma in the cf-ch20, cf-eu11 region then they just get it) - https://github.com/kyma-project/kyma-environment-broker/pull/888
• [ ] 3) Docs update
  • [ ] 3.1) help sap docs update: mention cf-ch20
  • [ ] 3.2) help sap docs update: remove section about whitelist and what to do if not allowed
  • [x] 3.3) update opensource docs: see: https://github.com/kyma-project/kyma-environment-broker/pull/891
• [ ] 4) RN

Link

See what we already have in that topic: https://github.com/kyma-project/kyma-environment-broker/blob/main/docs/contributor/03-20-eu-access.md

[ralikio]

Waits for registration by @PK85