Be more thorough in generating PATHs from older packages
Be more thorough in generating PATHs from older packages

With the addition of the new runtime environment variables feature, it
has become apparent that our fallback logic for extracting `PATH`
variables from older packages built before version 0.50.3 was not as
complete as it needed to be.

Now, when we encounter a dependency that does not have a
`RUNTIME_ENVIRONMENT` metadata file, we not only take the `PATH`
metadata from that dependency, but also from its _transitive_
dependencies.

This should more fully replicate the older behavior of the Supervisor,
which assembled this information at runtime prior to the 0.50.3
release.

Signed-off-by: Christopher Maier <b4598f17a90ef80817bae8ad6c37249740caafb4@chef.io>

georgemarshall/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,georgemarshall/habitat,nathenharvey/habitat,nathenharvey/habitat,georgemarshall/habitat,habitat-sh/habitat,nathenharvey/habitat,rsertelon/habitat,nathenharvey/habitat,rsertelon/habitat,georgemarshall/habitat,habitat-sh/habitat,rsertelon/habitat,georgemarshall/habitat,habitat-sh/habitat,georgemarshall/habitat,rsertelon/habitat,nathenharvey/habitat,rsertelon/habitat,georgemarshall/habitat,nathenharvey/habitat,habitat-sh/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,georgemarshall/habitat