Fix Visual Studio 2019 v16.6 compiler warnings/errors
Summary:
- Missing include in berryQtStyleManager.h
- Became infected with warning as error from PythonQt regarding unnamed typedef structs
Test Plan: Already compiled on new e230-nuc03 client with latest version of Visual Studio.
Reviewers: O1 MITK Reviewer Group I, O3 MITK Reviewer Group II, floca
Reviewed By: O1 MITK Reviewer Group I, O3 MITK Reviewer Group II, floca
Maniphest Tasks: T27482
Differential Revision: https://phabricator.mitk.org/D322