saip: add numeric_base indicator to ConfigurableParameter and ParamSource
By default, numeric_base = None, to indicate that there are no explicit limitations on the number space.
For parameters that are definitely decimal, set numeric_base = 10. For definitely hexadecimal, set numeric_base = 16.
Do the same for ConfigurableParameter as well as ParamSource, so callers can match them up: if a parameter is numeric_base = 10, then omit sources that are numeric_base = 16, and vice versa.
