Draft: allow to clean system update entries
requested to merge lduboeuf/lomiri-system-settings:ubports/xenial_-_cleanupsysupdates into ubports/xenial
Sometimes update image list is not accurate or we can't apply the update. A work around is to clean manually or via UTTT cache and app datas.
the idea is to be able to clean the entry list directly on the UI, this will cancel any pending updates, reset the database and re-run a check for update:
Edited by Lionel Duboeuf