Renamed all instances of Url to Uri

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | yes
| Tests pass?   | no - depends on https://github.com/symfony-cmf/RoutingAuto/pull/9
| Fixed tickets | #82 
| License       | MIT
| Doc PR        | TBA