chore: improve test coverage

[urangel]

Description

This adds some test coverage around the NTAuthStore properties and the parseAllProperties method.

Motivation and Context

Improving code quality.

How Has This Been Tested?

These tests were run on my mac laptop. I updated some of the test labels to [WindowsOnlyFact] since they were calling windows specific APIs and failed to run on my OS.

Types of changes

• Chore (a change that does not modify the application functionality)
• 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:

• Documentation updates are needed, and have been made accordingly.
• I have added and/or updated tests to cover my changes.
• All new and existing tests passed.
• My changes include a database migration.