Add class label to plot segments

[parevalo]

Feature request: It would be nice to be able to see the class label along with the RMSE next to the segments, even if it is just the class number. Ultimately, the script could check a lookup table in order to assign proper text labels. If there are multiple saved results, there should be a way to select one or each of them.

[ceholden]

Depends on #71 for the YATSM series of drivers. For CCDC results drivers, we'll also need to read from the TSFitMapMat files.

Steps:

1. At least recover the classification label as an integer and plot that
2. In the YATSM config, allow the user to add in the path to a LUT CSV that translates IDs to text descriptions