Make the license names match the SPDX standard

[kit-ty-kate]

opam 2.2.0 will bring a full SPDX format support (see ocaml/opam#4768).
This PR normalizes the license names to match the standard:

• The WITH keyword has to be uppercase according to the standard. opam < 2.2.0 was too permissive.
• Several license ids (e.g. LGPL-2.1 instead of LGPL-2.1-only or LGPL-2.1-or-later) are deprecated since SPDX 3.0
• This PR also fixes various license name mistakes from older packages (I've only done the obvious ones, there are still 392 packages to fix manually)

[avsm]

I've not verified each license obviously, but eyeballed the diff and checked that it only touches the license field and the changes themselves are normalisations. Thanks Kate!

[avsm]

Merging before the conflicts kick in :)