Merge Async Read / Write Operations into a single Read / Write Operation.

• AsyncWriteOperation into WriteOperation is a simple merge
• AsyncReadOperation merged into ReadOperation requires an additional type parameter This is due to async and sync cursors have different types.
• Added extra ReadOperations interfaces to represent:
  • Read operations that return the same type for both sync / async
  • Read operations that represent cursors
• Removed SyncOperations and AsyncOperations builders which both use the same Operations builder class.

This proposal fell out of initial work done for JAVA-5197 and turned out to be a rabbit hole that wasn't related to that work. However after discussion at standup we decided the idea may have some merit.