Combine LZ and DMZ develop branches

[aloftus23]

fixes #20

🗣 Description

Combine the LZ branch with the DMZ develop.

Required:

• Create LZ stages (staging and prod) in terraform
• Create LZ stages (staging and prod) in serverless framework
• Make sure terraform resources like EC2 are only created in DMZ
• Make sure serverless resources like SQS are only created in DMZ

💭 Motivation and context

Make deploying in all environments and ST&E scanning much easier.

Also, decreases the risk of losing any code updates when moving into the LZ.

🧪 Testing

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All future TODOs are captured in issues, which are referenced
  in code comments.
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release.