Basic Segmentation: Validation errors unhelpful

[jessnoo]

there are validation checks happening on values within the input data for Basic Segmentation. The error messages presented when a check fails aren't helpful for the user and the valid value ranges aren't documented in the help.

Need to:

• improve the error messages to help the user know how to fix the problem
• add details into the solutions site doc for what valid values are for the tool

@jmhauck fyi