(Follow up to SERVER-119302) From investigation in SERVER-115408, we determined that one of the key interactions between the checkpoint manager and the log server manager is that the 
LogServerManager provides getCheckpointManager() and a couple bare delegate functions to provide access to CheckpointManager to other classes (state machine and repl coord). 

This ticket is part two to remove the delegates and give them pointers to the CM directly.

Acceptance criteria:

Remove delegates; in cases where ReplicationCoordinator or SlsStateMachine "reach in" and work with the CheckpointManager directly, give them pointers to the CheckpointManager instead. Remove getCheckpointManager() member function.