Internal: Consider ways to extend and rename/alias rules

[hzeller]

In #901 the undersized-binary-literal rule was extended to not only understand binary but also octal and hex numbers.

While in this case, the naming still somewhat makes sense (after all, we provide binary numbers), there might be other cases in which renaming a rule to reflect the wider range might be desirable (undersized-numeric-literal ?), while also having a backward compatible 'old' name, specifying an alias

undersized-binary-literal ::= undersized-numeric-literal with configuration="bin:true"

There should be an easy, low-boilerplate overhead in the code to do that.