Support named parameters with nested routes

Basic repeatable code:

``` js
const routes = {
 '/:id': {
  "/": id => `${id}`,
  "/profile": id => `${id} profile`
 }
}

const {path, value} = switchPath('/1/profile', routes)

/* actual
path === '/1/profile'
value === '1'
*/

/* expected
path === '/1/profile'
value === '1 profile'
*/
```
