Make pacman system upgrade optional

Split upgrade and refresh options when installing a pacman package.

refresh option control pacman -Sy
sysupgrade option control pacman -Su

Important note: refresh=True no more upgrade your whole system.

Linked to this: https://github.com/saltstack/salt/pull/10519/
Allow pacman upgrade to don't refresh the database

The default behavior is still to refresh before upgrade.
Merge pull request #10519 from seblu/develop

pacman: Don't upgrade by installing a package