Add Support for SSO (#1051)

* Add Support for SSO

This commit adds support for the SSO credential provider, which enables the aws-config to support using SSO when specified in `~/.aws/config`.

* Rename & add test of configuration failure

* Add SSO to the smoke test list

* CR improvements

- Improve error messages
- zeroize token
- add track_caller to improve test failure error messages

* Apply suggestions from code review

Co-authored-by: John DiSanti <jdisanti@amazon.com>

* Update changelogs

Co-authored-by: John DiSanti <jdisanti@amazon.com>