Have two versions of install_label GtkLabel
It should start with:
- “To add more” if there are already some packages in the list.
- “To do so” if there are no packages in the list.
See 10a5701da5 which fixes the string when there are packages but breaks it when there are none.
Feature Branch: bugfix/15587-adapt-install-label
Parent Task: #15567 (closed)
Original created by @sajolida on 15587 (Redmine)