[WIP] add support for appengine application

[hasheddan]

Signed-off-by: hasheddan georgedanielmangum@gmail.com

Description of your changes

WIP support for GCP App Engine Application. This does not allow you to run workloads on App Engine, Application is 1:1 with a GCP project, so adding support for it allows the ability to then add Services to an Application.
TODO

• Fix up Identity Aware Proxy
• Unit tests
• Manual tests

Checklist

I have:

• Run make reviewable to ensure this PR is ready for review.
• Ensured this PR contains a neat, self documenting set of commits.
• Updated any relevant documentation, examples, or release notes.
• Updated the dependencies in app.yaml to include any new role permissions.
• Updated the package resources documentation to include any new managed resources or classes.