Angular v14 (feat|upcoming): Add Route.title with a configurable TitleStrategy

Users can provide custom strategies by extending TitleStrategy and adding a provider which overrides it.

The strategy takes advantage of the pre-existing data and resolve concepts in the Router implementation:

We can copy the Route.title into data/resolve in a non-breaking way by using a symbol as the key. This ensures that we do not have any collisions with pre-existing property names. By using data and resolve, we do not have to add anything more to the router navigation pipeline to support this feature.