XD-2251 Create the SSLContext early and cache it

Caches the SSLContext right after bean creation, preventing expensive operations such as reading the keystore, to take place more than once. The SSLEngine needs to be created per Netty Channel, as it is not thread-safe.
XD-2215: Fixed NPE in ZooKeeperModuleMetadataRepository

Modified ZooKeeperModuleMetadataRepository to eliminate NPE.

Introduced Id class to ModuleMetadata, which is used
to identify instances of ModuleMetadata in
ModuleMetadataRepository.

Deployment unit status in ModuleMetadata is now final.

Simplified implementation of deployment unit status
retrieval.

Utility for reporting client requests from ZK log
XD-1877, XD-2245 refactored and enhanced gemfire module.xml and added Gemfire integration tests

Code polished based on code review comments

Renamed file with proper capitalization
New File Added