Changes to how Disconnect-Rubrik handles variable cleanup

[jaapbrasser]

Description

Current Behavior:

When Disconnect-Rubrik is ran, depending on what method of connection is used, either

Expected Behavior:

Steps to Reproduce:

Please provide detailed steps for reproducing the issue.

Connect-Rubrik -Credential $Cred
Disconnect-Rubrik

$RubrikConnection & $RubrikConnections are not cleared

Context:

All versions of PowerShell & Windows PowerShell are affected

Related Issue

Resolve #598

Motivation and Context

Fix inconsistency in how $RubrikConnection(s) variables are cleaned up

How Has This Been Tested?

Ran current unit tests and created new unit tests to cover the changes

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

Go over all the following points, and put an x in all the boxes that apply. If you're unsure about any of these, don't hesitate to ask. We're here to help!

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTION document.
• I have updated the CHANGELOG file accordingly for the version that this merge modifies.
• I have added tests to cover my changes.
• All new and existing tests passed.

[mwpreston]

LGTM