Install .vapi, .deps, .h files for the Vala libraries. Also install the
data files. .deps files have to be manually generated, there's a feature
request for automated generation at
https://github.com/mesonbuild/meson/issues/9756.
Import the gnome module globally.
Install dependencies on Meson CI.
Basic configuration of qlite, xmpp-vala, the Dino library and the Dino
application are supported. There's no support for the plugins.
This e.g. enables using the Vala language server.
