framework/controller: Improve support for injecting request-specific dependencies

[matthewmueller]

The following PR improves support for injecting request-specific dependencies that include *http.Request and/or http.ResponseWriter. This will form the basis for higher-level APIs like sessions.

This PR also changes the provider signature to be easier to generate. Now all hoisted dependencies come before all external dependencies. Within hoisted and non-hoisted dependencies, they're sorted in alphabetical order.

Finally, this PR also refactors the controller generation code to use *di.Provider instead of the home-grown structs in the controller state.

Todo:

• Fix issue with log package in controller interfering with log package in app.