Add integration tests for supported event stream operations (#676)

* Add support for waiting for the requests to close

* Fix excluded `aws-auth-providers` build

* Add integration test for `transcribestreaming`

* Add integration test for S3 SelectObjectContent

* Validate all request events in the Transcribe streaming test

* Added comment to `decode_frames`

* Fix `aws-config` tests

* Remove trailing whitespace

Co-authored-by: Russell Cohen <rcoh@amazon.com>