refactor HistoryTest.cpp to test the history using HistoryViewModel

[rudyhuyn]

Fixes #783

Description of the changes:

• Modify HistoryTest.cpp to use HistoryViewModel instead of CalculatorHistory. in order to test the full stack and not only the CalcManager part.
  • ⚠ one of the big difference is how the history items collection is ordered.

Also:

• Expose some methods from CalcManager (a native library) via StandardCalcViewModel, making them accessible from another windows runtime library.
• make PropertyNames public instead of internal so other (dynamic) libraries can use them.
• move Utils::GetStringValue from CalcViewModel to CalculatorUnitTests

How changes were validated:

• Manually

[sanderl]

Just a few changes needed that I saw. It looks like there are merge conflicts. Once the merge conflicts are fixed, I'll buddy build and buddy test.

[ghost]

This pull request has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 7 days. Thank you for your contributions to Windows Calculator!

[rudyhuyn]

!rebased