Bug 250688

GObject property nicks and blurbs are mostly useless and require thinking to write, so we should get rid of almost all of them. This is especially beneficial for translators: most (but not all) of our nicks and blurbs are translated, and it's wasted effort to translate something that is never used. GTK has already removed its nicks and blurbs in https://gitlab.gnome.org/GNOME/gtk/-/issues/4904, and we should follow.

Well, mostly. An exception is WebKitSettings. MiniBrowser is using the nicks and blurbs to programatically create its settings dialog. This is probably the best use of nicks and blurbs that I've ever seen. Keep the nicks and blurbs here to not break this. I've also not touched the deprecated GTK DOM API, since all of these files will be deleted in the distant future, and none of them are marked for translation, so they're not actively hurting anything.

Other known uses of nicks and blurbs:

 * GStreamer supposedly uses these for its documentation. (We don't; gi-docgen does not look at them.)
 * Glade uses these, but Glade is deprecated in favor of Cambalache, which does not.