libgltf, glTF models, collada etc ?

[Caolán McNamara]

So we have support for glTF models in LibreOffice. There's is then the
bug tdf#103884 that they don't work under gtk3. One reason they don't
work in gtk3 is because gtk3 opengl support is restricted to the core
profile and libgltf uses a few of the older non-core things.

e.g. would need these fixes...
https://gerrit.libreoffice.org/#/c/41994/
https://gerrit.libreoffice.org/#/c/41998/

There's still some other problems that need fixing, but before spending
any more effort on this...

is this whole 3d model feature still something we still actually want
to have ? It seems to me to be of marginal utility.