XD-2026 Tweaks for storing admin metadata into zookeeper

- New RuntimeRepository for admin metadata
- Following same concepts used in ContainerRepository
- Store real bind port from tomcat into this repository. RuntimeAttributes
  based on ContainerAttributes except group info has been removed.
- Metadata updates happen in DeploymentSupervisor where update logic
  is based on concepts from ContainerRegistrar.
- ZK path /xd/admins is moved over to /xd/adminelection and /xd/admins
  is now solely used for metadata in a same way that /xd/containers.
- ZooKeeperRuntimeRepository doesn't use caching because we don't
  expect a lot of runtime admin containers and we don't read that often.

XD-2026 Fixes for review

- Renaming ContainerRuntime and RuntimeAttributes to
  Admin and AdminAttributes respectively. Follow same
  rename logic throughout the rest of the classes.
- Added sync block guarding zookeeper within app events.
- Registration now before election.
- Delete old registration instead of waiting zk to do it.
- Some other small fixed which weren't catched in review.