feat(apollo): Add Apollo Appsync Extensions

[mattcreaser]

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes:

• Adds the Apollo AppSync Extensions libraries. This is a new library that allows customers to use Apollo GraphQL to connect to AppSync.

How did you test these changes?

• Unit Tests
• Integration Tests
• Manual Testing

Documentation update required?

• No
• Yes Documentation is in progress

General Checklist

• Added Unit Tests
• Added Integration Tests
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.