BUG: Coverity 1103189: Big parameter passed by value in FindSampleBound

This also refactors the implementation of FindSampleBound, renaming a
variable to be more maintainable and slightly improving its performance
by preventing 1 unnecessary copy of a MeasurementVector.

Change-Id: I7646b04fd415a9377fd30f16ea4adc7d2f3d011e
Merge topic 'Statistics_SampleBounds2'

f8438305 BUG: Coverity 1103189: Big parameter passed by value in FindSampleBound