Add a basic Package type that does not depend on the standard library

[paulcadman]

The problem

As noted by @lukaszcz : "... typechecking tries to evaluate Package.juvix, so I can't debug the changes piecemeal on small examples, because the standard library is always needed"

We need a way to define a Juvix package without depending on large amounts of existing Juvix code, so we can run examples while changing the Juvix compiler behaviour (syntax, typechecker, ...).

Proposal

Add a new Package type that has a single constructor:

module PackageDescription.Basic;

type Package := basicPackage;

One could then write the following Package.juvix:

module Package;

import PackageDescription.Basic open;

package : Package := basicPackage;

This would behave as if you'd defined a project using an empty juvix.yaml file, i.e a Package with all fields set to default.

• We could add a flag to juvix init to generate this Package.juvix instead of the one using PackageDescription.V1.
• We could use this Package type in the test suite packages to speed up the test suite.