feat(nix): packages.${system}.ags.wrap function

[ys5g]

Motivation: overring extraPackages resulted in re-compilation of the ags go binary, which was a bit annoying.

Would it be better to implement this function in the passthru attributes of ags and agsFull?

Like(in nix/default.nix)

{
# ...
  passthru.wrapAgs = import ./wrap.nix;
# ...
}

[Aylur]

This just adds unnecessary noise imo. The purpose of agsFull is that you can start out with it without worrying about what packages you want. Then when you have a somewhat functioning shell you are happy with you can cherry pick dependencies. You won't be adding extra packages very often and go builds are fast anyway.

[ys5g]

If you meant noise on the user side, putting it into passthru.wrapAgs would get rid of it. I think I should have done that from the start. I'll try getting that refactored in a day.
Imo, it doesn't seem like it is noisy on ags's side.

This PR isn't that important so, if you want to, you can close it.