* EncryptKeyProxy server APIs for simulation runs.
Description
diff-2: FlowSingleton util class
Bug fixes
diff-1: Expected errors returned to the caller
Major changes proposed are:
1. EncryptKeyProxy server APIs:
1.1. Lookup Cipher details via BaseCipherId
1.2. Lookup latest Cipher details via encryption domainId.
2. EncyrptKeyProxy implements caches indexed by: baseCipherId &
encyrptDomainId
3. Periodic task to refresh domainId indexed cache to support
'limiting cipher lifetime' abilities if supported by
external KMS solutions.
Testing
EncyrptKeyProxyTest workload to validate the newly added code.