Move Universe library to external package

[shykes]

Currently the dagger stdlib is embeded in the dagger binary. This is a short-term solution, meant to save time in the early phases of development. But the plan is to change how stdlib is distributed before launch.

The issue is a placeholder for planning purposes.

[aluzzardi]

Related to #1335

From duplicate #1340:

This was attempted in the past but postponed because of technical challenges.
Assigning to @samalba since you have the most context on this.
Doesn't mean we're going to do it for the Europa release, but at least now we have an owner.

[shykes]

Closing this, since the real issue is changing the package distribution method, from embedded in the dagger binary (currenty method) to downloading from a git repository (desired method). The location and layout of the git repository are an implementation detail, that we can worry about later. For now, keeping everything in the same repo is fine. It even has a short-term benefit: more PRs, issues and stars concentrated on a single repo, which will boost visibility on github and thus help with adoption.