[SPARK-3130][MLLIB] detect negative values in naive Bayes

because NB treats feature values as term frequencies. jkbradley

Author: Xiangrui Meng <meng@databricks.com>

Closes #2038 from mengxr/nb-neg and squashes the following commits:

52c37c3 [Xiangrui Meng] address comments
65f892d [Xiangrui Meng] detect negative values in nb