Feature: configurable connectors for AWS clients (#1918)

* feature: make HTTP connectors configurable

* add: test for HTTP connector configuration customization
add: impl<B> From<TestConnection<B>> for HttpConnector
add: impl From<CaptureRequestHandler> for HttpConnector
add: impl From<NeverConnector> for HttpConnector
add: impl From<ReplayingConnection> for HttpConnector

* add: to_vec method to AggregatedBytes
update: method param names of FluentClientGenerics.sendBounds to be more explicit
update: restructure s3/s3control tests to be uniform in structure

* update: CHANGELOG.next.toml
update: codegen `impl From<&SdkConfig> for Builder` to support HTTP connectors

* update: CHANGELOG entry references

* add: missing copyright header

* fix: clippy lint

* format: run cargo fmt

* format: run cargo fmt on aws_smithy_client::dvr modules

* format: run ktlintFormat

* refactor: use from_conf instead of from_conf_conn
remove: from_conf_conn

* update: impl From<SmithyConnector> for HttpConnector
remove: other From<T> for HttpConnector impls
update: HttpConnector config setter examples

* update: CHANGELOG.next.toml

* Update CHANGELOG.next.toml

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

* update: CHANGELOG.next.toml
remove: obsolete test
update: `ConfigLoader::http_connector` setter method

* Update CHANGELOG.next.toml

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

* Update CHANGELOG.next.toml

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

* Update CHANGELOG.next.toml

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

* Apply suggestions from code review

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

* update: aws_config::loader::ConfigLoader doc comments
update: CHANGELOG.next.toml examples

* fix: doc issues
add: reëxport aws_smithy_types::endpoint module to aws-config

* format: run rustfmt in the weird CI way to get it to actually format.

* fix: incorrect reëxport

* add: "aws_smithy_http::endpoint" to allowed external types for aws-config

* update: move `hyper-rustls` to deps so that it doesn't break exotic arch CI check

* remove: `hyper-rustls` dep because it's not actually needed

* fix: aws-types dep issue blocking exotic arch CI check

* fix: broken doc comment

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