message: Add changelog for
  Coauthor: Ahson Khan
diff: - Removed `Azure::Storage::Common::PackageVersion`.
  - Moved `ReliableStream` to internal namespace.
  +- Removed `HttpGetterInfo` and `HTTPGetter` from the `Azure::Storage` namespace.
  ## 12.0.0-beta.9 (2021-03-23)
  