An Extension of volgo.Vcs to use with Base

[Volgo_base] is a library that extends the [Vcs] library with additional modules and functionalities to improve compatibility with programs using base.

For example, it adds [Comparable.S] to all container key modules so that they can be used with base-style containers such as [Map] and [Hashtbl].

It also exports a module [Vcs.Or_error] to make it easy to use [Vcs] with the [Or_error] monad.

The library is designed to be used as a drop-in replacement for [Vcs]. To achieve this, it includes a single module named [Vcs] which must be set up to shadow the regular [Vcs] module.