Normalize runtime crate manifests and apply correct version numbers (#755)

* Rename `protocol-test-helpers` to `smithy-protocol-test-helpers`

* Add missing licenses to runtime crates

* Normalize runtime crate manifests

* Remove unused dependencies

* Make `pretty_assertions` version consistent

* Add repository to generated SDK crate manifests

* Create `smithy-rs-head` crate version tag

* Set correct crate versions when relocating runtimes

* Run version replacement only on Cargo.toml files

* Revise head version number from RFC feedback

* Rename `smithy-protocol-test-helpers` to `smithy-protocol-test`

* Incorporate feedback

* Update changelogs

* Fix rename issues

* Fix EventStreamMarshallerGeneratorTest