Initial PR for the feature/GraphingCalculator feature branch, part of #338.
The feature incorporates a proprietary Microsoft-owned graphing engine to drive graphing experiences in the Windows Calculator app. Due to the private nature of the graphing engine, the source available in the public repo will make use of a mock graphing engine. See README.md for more details.
This PR simply serves as a base for future feature development. As such, the PR will be immediately merged. Feedback on the content of this PR, and on the feature in general, is encouraged. If there is feedback related to the content of this specific PR, please leave comments on the PR page. We will address the comments in future PRs to the feature branch.
Remove LayoutAwarePage, SuspensionManager, and other suspend-resume handling code. SuspensionManager::SaveAsync and related methods weren't actually called anywhere. I didn't attempt to remove the serialize/deserialize code at the ViewModel layer, although much of that is likely not needed either.
We may decide we want to persist more state through a suspend-terminate-resume cycle (as the app might have done a long time ago). But if we decide we want that, we should not use a persistence mechanism that's closely coupled to frame navigation.
