Feat/isd 1567 rebase

[codethulu]

Applicable spec: N/A

Overview

Include gh and unzip functionality from the Ubuntu Archives. Included some simple checks in the e2e test file, to ensure the packages have been installed correctly.

Rationale

This functionality was not currently present, and has been requested as an addition.

Juju Events Changes

Juju events should not be affected by this change.

Module Changes

No changes to any module functionality.

Library Changes

Charm libraries are unchanged.

Checklist

• [x] The charm style guide was applied
• [x] The contributing guide was applied
• [x] The changes are compliant with ISD054 - Managing Charm Complexity
• [ ] The documentation is generated using src-docs
• [ ] The documentation for charmhub is updated.
• [x] The PR is tagged with appropriate label (urgent, trivial, complex)

This PR does not warrant any new charm documentation due to the nature of this change.