Add support for disable MustCleanup in TCheckHashRecursiveRemoveConsistency.

If the user calls 'gROOT->SetMustCleanup(kFALSE);'
the RecursiveRemove mechanism is disabled, nonetheless we still need to have
TCheckHashRecursiveRemoveConsistency return the intended answer.
So the disabling is now 'lifted' for the object created by TCheckHashRecursiveRemoveConsistency.

This fixes ROOT-9369