Improve deep link management

Improve deep link from remote notifications and user activity. Centralize deep link generation like in this [blog post](https://medium.com/blacklane-engineering/coordinators-essential-tutorial-part-ii-b5ab3eb4a74).
The `AppCoordinator` will then be able to build the view stack according to generated deep link object.

Things to verify and decide:
- Use one enum for all kind of deep links
- Use a flat tree or a composable tree to represent deep linking