Copy non-service integration tests into SDK root tests directory (#2255)

* Copy non-service integration tests into SDK root tests directory

For tests in `aws/sdk/integration-tests` that are not named after a
service module, copy them into the SDK's root `tests/` directory so that
they are run as part of CI on the entire SDK.

* Add missing fields to integration test manifests
* Remove tests from root workspace
* Explicitly exclude the root tests from the root workspace