Proposed changes

Add an AWS AppConfig API Data Source

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

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• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc.

We need an AppConfig data source, and this was a simple addition alongside the lambda, dynamo, and athena plugins.

• Add an AWS AppConfig API Data Source with several query options. Not all
  are implemented, but most of the main ones are.
• Small fix to add 'no' option to list