This moves all of the tcp target functionality into a tcp package. It
also establishes a Register function in the target package to allow
specific target types to be registered at initilazation time. When
registering, a target type needs to provide its Subtype, as well as some
RepositoryHooks that are used by the target Repository.
* 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>