Rename `aws_types::config::Config` to `sdk_config::SdkConfig` (#1241)

* rename: aws_types::config::Config to sdk_config::SdkConfig
update: code affected by SdkConfig rename
update: CHANGELOG.next.toml

* update: reëxport SdkConfig from aws_types root module

* Update aws/rust-runtime/aws-config/src/lib.rs

* Update CHANGELOG.next.toml

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

* add: deprecated config helper
update: use reexported SdkConfig in docs referencing it

* fix: bad doc link
fix: wrong deprecation version

* Revert "fix: bad doc link"

This reverts commit eaa1b68e3b5e7c15f655cd294135c40f9b52e178.

* fix: try new link style

* add: deprecation notice for `aws_types::config` module

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