[bug#63604] Branch "tex-team-next" in need of review

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

I just pushed an update on tex-team-next branch.

The biggest change is about hyphenations. I created one big package
containing all hyphenations, named `texlive-hyphen-complete'.
`texlive-hyphen-base' still exists for low-level packages, such as
`texlive-tex', but every other hyphenation related package has been
deprecated and removed.

Also, the build system now generates TeX formats on demand, with the
#:generate-formats keyword.

At this point, with the following command,

  ./pre-inst-env guix shell --pure texlive-bin texlive-ec texlive-latex-base texlive-babel-french texlive-carlisle -- latex /tmp/test.tex

I can compile the following LaTeX document _without any hyphenation
warning_:

--8<---------------cut here---------------start------------->8---
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[french]{babel}
\begin{document}
Success!
\end{document}
--8<---------------cut here---------------end--------------->8---

So, what's next?

- Install executables (copied from `texlive-bin') along with the texlive
  package, when appropriate. The more packages you install, the less you
  need `texlive-bin'. Ultimately, I want to get rid of `texlive-bin' as
  a native input for every package. I think it should be limited to the
  first few packages needed to build the rest. If that works, the
  #:texlive-bin keyword can go away.

- Replace `texlive-latex-base', which doesn't exist in TeX Live, with
  `texlive-latex-bin'.  Consequently, `#:texlive-latex-base' would be
  renamed `#:texlive-latex-bin'.

- Limit propagated inputs to the bare minimum, as defined in Tex Live,
  and, at the same time, introduce collections and schemes. For example,
  `texlive-scheme-basic' would replace `texlive-base'.

Regards,