Add support for import of geometry and results for main grid. Currently no support for LGR.
Add selection in Preferences to either use libecl or opm-common for grid import.
If RESINSIGHT_DEVEL flag is set, display reader in an Eclipse case to make it possible to compare Eclipse and opm-common in same project.
Add more includes to custom-opm-common to be able to support this functionality. opm-common is unchanged.
* #7575 Summary HDF : Do not import summary if no UNSRMY file is found
* #7575 Summary HDF : Add optional check on time stamp of h5 file
* Use std::filesystem to check file access
* Do not keep h5 file open