Scala Installations support

Adds a valid, persistent, best-effort scala library bundle setup on classpath after the choice of a scala desired source level in project-scopes compiler options.

Operates by modifying and serializing the scala classpath container.

Does not include scala-installation registry edition yet.
I am not sure what is the interest of using tuples in this case. `same` could be a `(x: T, y: T) => Boolean` and then avoid all the tuple boxing.

And for `sameEntries`, I would create a `containsAll` local method.