clean up of old files inherited from initial set up of repo

[mikeoleary]

I am pretty sure this is leftover from when we were converting from YAML and the AWS team's start on this:

1. file in question is: "/VCP/aws-scca-vdss-stack-singleAZ.template.json" - I believe this can be deleted but we should test.

2. file "/aws-quickstart-scca-transit-gateway-stack.json" - this should be moved under a folder. It is still referenced so we need to change the reference to it in the root template.