Map GAP dependencies to Julia dependencies?

[fingolfin]

There is some deactivated code for doing this already in generate_wrapper.jl.

The idea is that e.g. GAP_pkg_cvec should depend on ``GAP_pkg_io(and dousing GAP_pkg_io`) because `cvec` depends on `io`. With that in place, it will suffice to do this to load cvec into Julia:

using GAP_pkg_cvec ; GAP_pkg_cvec.load()

But there are a bunch of questions:

• figure out a way to get the UUID of e.g. GAP_pkg_io when it is not yet in the (resp. "a") registry
  • perhaps just parse the GAP_pkg_*/Project.toml files and extract the UUID from there?
• how to map version restrictions in GAP's PackageInfo. to compat strings
• ...