continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.
cherrytree - A hierarchical note taking application, featuring rich text
and syntax highlighting, storing data in a single xml or sqlite file.
This commit also adds PyGtkSourceView - a Python wrapper for the GtkSourceView widget library.
Official page http://www.giuspen.com/cherrytree