feat: load managed policies locally

[hoffa]

Issue #, if available

Description of changes

Faster and more resilient transforms by bundling the name-to-ARN managed policy map with the code.

The ARN of a managed policy name is determined by Translator in the following order:

1. From the managed_policy_map argument. Can be None.
2. From the bundled managed policy map.
3. From the get_managed_policy_map function. Must be efficient to call, as it can be called multiple times within a transform.

Got the managed policies from my personal account using:

aws iam list-policies --scope AWS | jq '.Policies[] | {(.PolicyName): .Arn}' | jq -s add --sort-keys

Originally cached get_managed_policy_map() within the Translator instance, but anecdotally Translator is instantiated in hot paths, so letting the caller do the caching is simpler to integrate.

Description of how you validated changes

Checklist

• Adheres to the development guidelines
• Add/update transform tests
  • Using correct values
  • Using wrong values
• Add/update integration tests

Examples?

Please reach out in the comments if you want to add an example. Examples will be
added to sam init through aws/aws-sam-cli-app-templates.

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

[aahung]

gogogo

[aahung]

🎉

[acristin]

Just a minor complaint and two questions.