[RFE] improve image creation script to support multiple base image choices

## Current situation

image_creation test script was built based on limited testing with Ubuntu as the base image with some image-specific assumptions (e.g., netplan networking). This might cause issues when used with other base images.

## Impact

Testing might have undefined/unexpected behaviors when used with other distros as base images.

## Ideal future situation

Test script should work against different distros as base images. It also should document which base images have been tested to work well.

## Implementation options
Two important issues to handle:
1) Networking: we should identify which networking software is used with the existing image (ifup-down, netplan/systemd-networkd, systemd-networkd, NetworkManager, wicked, etc...) and ensure that the basic network configuration to perform dhcp on the primary interface is written since azure-init relies on primary nic's wireserver/imds routing to report provisioning complete.
2) Package management system: apt/yum/dnf to install required software and/or to remove existing packages (walinuxagent/cloud-init)