Introduce Instance Refresh for ASG module

[sebastianczech]

Is your feature request related to a problem?

Feature request is related to instance refresh, which is currently not configurable in asg module.

Describe the solution you'd like

In order to allow customers refresh VM-Series instances in controlled way defined in instance_refresh block e.g. in order to upgrade firewalls by changing PAN-OS version in launch template, module asg needs to be extended.

Most of the options for instance_refresh block should be exposed as variables with default values e.g. while allowing customer to define instance_warmp set default to 20 minutes or more.

Additionally current aws_launch_template settings needs to be reviewed and adjusted e.g. make launch template version configurable for a refresh to trigger (keep defaulted to $Latest).