Remove -VpgIdentifier Parameter from Get-ZertoRecoveryReport function

[wcarroll]

Description

Removed the -vpgIdentifier parameter from the Get-ZertoRecoveryReport function as it is unused.

Related Issue

Fixes #60

Motivation and Context

The parameter is not accepted by the API and is ignored. Removing it from the function as an option.

How Has This Been Tested?

Built the module and the parameter was no longer an option. Ran all integrated tests.

Screenshots (if appropriate):

Types of changes

• [X] 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:

• [X] My code follows the code style of this project.
• [X] My change requires a change to the documentation.
• [X] I have updated the documentation accordingly.
• [X] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [X] All new and existing tests passed.