Casing functions, from/to camel, kebab, pascal and snake. An optional
coersion function can be provided to change the end result into another type,
(typically keyword, symbol or simliar).

A lot of the code could have been generated, but keeing it explicit was an
explicit choise to avoid macros and similar in this code.

Coerce functions that takes two strings, a namespace and a name,
and turns it into something.

The core casing functions, operating only on strings. Some functions
here are very trival and could be inlined elsewhere, but exists for
completeness for the consuming code.