Refactor airgapped scripts to work for any bundle version

[NohaIhab]

Context

Refactor the scripts to be more generic (no hardcoding images/charms/pkgs versions) so that they work for any bundle version.

Update:

• hardcoding of testing images in the scripts got addressed by #1038
• TODO: eliminate the hardcoding of charms, currently we have a deployment script for each version (1.8, 1.9)

What needs to get done

1. Look into the hardcoded parts of the airgapped scripts
2. Refactor the scripts to be dynamic for those previously hardcoded parts

Definition of Done

the airgap scripts are refactored as detailed above