packaging: Added backup DB functionality to setup

This patch adds user interaction asking to perform
the backup of the DB before performing an upgrade.
Prior to that it checks the available space and the
size of the DB and prompts the user with option to
perform the backup.

Change-Id: I8ccf8938099207b4e73bb947d1bb5fd673605071
Bug-Url: https://bugzilla.redhat.com/910070
Signed-off-by: Alex Lourie <alourie@redhat.com>