Use < 256 bins when data range is smaller than 256

## Use Case

Suggestion from a discussion w/ me and Kevin!

In cases where the data range is an integer and the range between the min and max is < 256, there are often many unused bins because the number of bins is always fixed at 256. There can also be pairs of adjacent bins that are filled/not filled due to slicing.

## Solution

- [ ] Update Histogram to use < 256 bins when data range is smaller than 256.
- [ ] Update LUT to handle Histograms with fewer bins.

## Alternatives

- Alternatives include adjusting this histogram view in the TFEditor in vole-app.