Allow to filter bandit warnings on severity or confidence
Both options are available on bandit command:
-l, --level report only issues of a given severity level or higher
(-l for LOW, -ll for MEDIUM, -lll for HIGH)
-i, --confidence report only issues of a given confidence level or
higher (-i for LOW, -ii for MEDIUM, -iii for HIGH)
We could just blindly add this or think about porting that to the common library and filter on the normalized output for every analyzers