Fix Get-WinVersionNumber

[dan-hughes]

Description

Matching logic was fragile and did not include any server versions. This should populate the 'Version' field in the Source WIM tab and allow patching to work.

Related Issue

Fixes part of #26, #27

Motivation and Context

How Has This Been Tested?

Yes

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.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.