Update MBM tutorial with modern, non-deprecated functionality and accurate description of defaults (#2466)

Summary:

* Use log acquisition functions
* Remove references to deprecated fixed-noise acquisition functions (now absorbed into more general acqfs)
* Correct inaccuracies in description of MBM defaults
* Removed unused imports

Reviewed By: mgarrard

Differential Revision: D57443923

Author: esantorella