BUG #13806. Remove min/max/mean from FindData.

Min/Max/Mean has issues with composite datasets (they work on per block basis
  which is not what the users expect), and they have MPI-related issues in
parallel esp. for composite datasets. Until those issues are fixed, we are
removing min/max/mean from the UI.

Change-Id: I593451d12ed7da75cafc1d44025aa483ce203a23
Merge topic '13806_remove_items_from_find_data' into next

518b34b BUG #13806. Remove min/max/mean from FindData.