Testing identified performance issues related to reading restart file name from summary files.
Make sure the reading of timesteps is done only when required in new function getFileInfoAndTimeSteps.
Add reading of restart file name using opm-common when opm-common is active. The performance of this reader is much better than resdata.
* Avoid ambiguous definition during unity build on Windows
* Add missing include
* Add Qt6 to expressionparser
* Add Qt6 to nightcharts
* Replace forward define of QStringList with include <QStringList>
* Use toMSecsSinceEpoch
* Use setContentsMargins
* Use one common variable for object name, use three ints
* Move enums to separate file
* Refactor use of enums
* Move implementation to cpp
* Refactor includes
