feat(role): Add package-specific global config files

Packages can now have a global (i.e. system-wide) config defined and
applied. If package is missing the config file is deleted. This is
helpful for example for Git where we want to define helpful aliases
for every logged in user and for tmux where every user should have
access to the tmux-resurrect session manager etc.

tasks/base-package-auxiliary-settings.yml

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: MIT
+- import_tasks: 'base-package-auxiliary-settings-tmux.yml'
+- import_tasks: 'base-package-auxiliary-settings-single-package-single-config.yml'