Add assimp

https://github.com/assimp/assimp

"Open Asset Import Library is a library to load various 3d file formats into a shared, in-memory format. It supports more than 40 file formats for import and a growing selection of file formats for export."

One currently can download it from https://github.com/YamanQD/AntWare/blob/ecb354a/subprojects/assimp.wrap#L2 but it needs https://github.com/YamanQD/AntWare/blob/main/meson.build#L14-L38 to work so guess it will some workaround to make it work, but using the referred workaround it works just great in my tests and I've used it https://github.com/capnramses/antons_opengl_tutorials_book/pull/45 also.

It is a package in Debian at least also.

Start by comparing the linked assimp.wrap from AntWare with the linked meson.build sections, then review how wrap requests in this repository are structured. Done means assimp is available through a working WrapDB package without relying on the external workaround described in the issue.

Written by the indexing model from the issue text.