Provide a `Pattern`-like API

[Nerixyz]

For Rust &str's, there is the standard library, there's the (still unstable) std::str::pattern::Pattern trait. It's used for methods like contains, starts_with, or matches.

This trait should be ported to work on types from this library (ideally, the trait from the standard library should allow different strings).

#1 requested string matching functions for the types exposed by this crate - Pattern would allow this by providing a std-like API.