Idea: extent LppType with min-max value range

[smlng]

add a parameter like range (list|tuple) of allowed values or min and max values which could also be used for testing, i.e. humidity or percentage would have an allow range of 0-100, or color would be 0-255 for red, green, and blue. Some data types might not have such well defined bounds, then leave the attribute empty or None.