[v2] S3 200 errors

[aemous]

Issue #, if available:

• S3 200 errors implementation boto/botocore#3276
• Fix event stream regression boto/botocore#3285
• Fix S3 200 Error handling boto/botocore#3288

Description of changes:

• Ports botocore changes to handle S3 HTTP 200 OK errors.

Description of tests:

• Ran and passed all unit & functional tests included in the PRs linked above.
• Ran all existing tests to ensure these changes don't break existing correctness.
• Added 1 functional test to ensure the CLI does not break given a response from botocore in the case a 200 OK error is encountered from S3.
• Manually tested the built application via S3 commands to ensure heuristic correctness of the product.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[ashovlin]

We can probably rebase on 23fe898 to fix the CI, but the change looks good to me.

Addressed changes