This moves the generated pb files to the `sdk` module. This allows third parties to make use of them if desired (e.g. in upcoming plugins) and moves away from the `gen` nomenclature in the directory, since we are going to be adding some extra interface functions to the messages.
* add new error funcs which take a ctx and deprecate existing funcs
* use context where available when writing error events
* remove circular internal/errors pkg dep
* suppress some chatty errors using errors.WithoutEvent()
* convert auth oidc funcs to take context where needed to write events
Co-authored-by: Jim <jlambert@hashicorp.com>