ENG-7341: Eliminate confusion and a possible race condition in
retrieving the current deployment config:
- Add the deploymentBytes to CatalogContext.  Use them instead of ZK
  where appropriate (anything other than initial deployment file read or
  @UpdateApplicationCatalog).
- Remove m_deployment from RealVoltDB, replace with the deployment from
  the current CatalogContext.
- Have CatalogContext generate the SHA-1 hash for the deployment bytes
  rather than expecting the hash to be provided along with the bytes on
  construction or update.
Merge pull request #1882 from VoltDB/eng7341

ENG-7341: Eliminate confusion and a possible race condition in