Bug 1648: Update Microstack Installation

Change installation to --devmode instead of --classic
Add --control to the init
Checks for state before creating some objects
Use the admin password generated by MicroStack install script
Update default security group to have fully open access
Update the initial image laod to 20.04
Added creation of an osm-ext network with router to external

Fixes bug 1648

Change-Id: I6038be023bf04f99000b0ac8aeec7f7bcf205204
Signed-off-by: beierlm <mark.beierl@canonical.com>