Function gix_utils::str::precompose

pub fn precompose(s: Cow<'_, str>) -> Cow<'_, str>

Assure that s is precomposed, i.e. ä is a single code-point, and not two i.e. a and <umlaut>.

At the expense of extra-compute, it does nothing if there is no work to be done, returning the original input without allocating.