Support app's with Dockerfile's

Adding support for app.Dockerfile = true.

[ ] Update apply logic
[ ] Update the Nitro API to inspect the containers ports and apply routing automatically
[ ] Update ssh to inspect the docker image
[ ] Look at way to "build" during nitro apply and determine if the app image is out of date, possibly nitro apply --build?
[ ] Disable features that we can't support with custom images

craftcms / nitro