Clean-up the codebase and the tests

Release a first version under the terms of the MPL 2.0

Fix build for recent version of syn

It looks like the `export` module is no longer a thing, so we directly
use `proc-macro2` insead.

Turn typed-urls-tera into a feature and introduce the actix feature

Derive Serialize implementation

Remove the Routing trait in favor of the more logical TypedUrl

Introduce typed-urls-tera

Implement Display

Make [to_string] public

Export TypedUrl

Rename into typed-urls

Clean-up the code

Initial commit