Add option disallow-numerical-affixes

[voidless]

Add option to disallow numerical affixes (prefixes and suffixes) without % symbols in the usage.

We've had a false negative with name "special2020" counting as used because of words "special" with usage "specialEvent". This is an expected default behavior (suffix_1 -> suffix_) that is why I've added an option to ignore such usages. With the option enabled it only counts usages like this (suffix_1 -> suffix_% or suffix_%d)

• [x] wrote unit tests

Usage:

path/to/fengniao --project . --disallow-numerical-affixes