Follow-up from "Version: Create sub-library Tezos-version.Value"

The following discussion from !8719 (merged) should be addressed:

• @hhugo1 started a discussion: (+2 comments)

  (I don't really understand the relation between the dependency on the universe and merging opam packages)

  I think this MR can be a good opportunity to cleanup the namespace a bit. As far as I see, there are only two values in this new library. We could drop the two submodules and have the lib expose a much simplier api.

  cat tezos_version_value.mli

  val version : Version.t
  
  val version_as_string_for_binaries : string