Mvpkaas 726|727|729: client secrets
Implements MVPKAAS-726, MVPKAAS-727 and MVPKAAS-729.
Briefly:
- create Rancher Token to perform TokenReview on the client cluster
- create Vault kubernetes auth backend on the cloud vault
- create vault policies for client pods and customer Keycloak roles
caascad-devopsandcaascad-devops-CLIENT_ZONEto allow management/usage of vault secrets