Allow for No Summarization of Values in the Matrix Visual

When setting values in the matrix visual there are no options to use a non-summarized value, instead they all must be summed, averaged, min, max, etc. We have seen this become an issue when using a DAX measure as the value. The measure will calculate correctly for each line item in the matrix but will total incorrectly at summary levels by summing all values or averaging all values rather than giving the measure for the data as a whole. Allowing for no summarization will allow the calculation to run as expected.