Upgrade Vault hvac and update Vault modules

[StefanDinu]

Upgrade the Vault code to use the new engine kv 2, which also uses namespaces. Accordingly, updating the Vault Python sdk hvac to a more modern version.

Description

• upgrade hvac module to >0.9.x
• modify Vault code to work with the new kv engine.
• slight styling changes because some lines were just too long. Wish we had some PEP8 or linting enforced.

Motivation and Context

The old Vault engine has been changed within Adobe Audience Manager.

How Has This Been Tested?

Built an ops docker image from my fork & branch, tested against CNS infrastructure that was using read_vault()

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• I have read the CONTRIBUTING document.
• All new and existing tests passed.

[amuraru]

please rebase and re-test