Support Compojure style parameter validation

Add support for regular expression based validation of individual parameters in URLs:

```clj
["/user/:id", :id #"[0-9]+"]
```

This provides a way to do some basic regex-based validation without losing the ability to generate URLs from routes.
I'll probably do this after I merge but it's worth mentioning we can be prescriptive here by adding some data that shows what we expected to receive and what we actually got. [For example](https://github.com/noprompt/garden/blob/master/src/cljx/garden/color.cljx#L520-L527).