Improve robustness related to update of Summary Plot Manager
Add RimSummaryMultiPlot
Move shared code into RiaSummaryStringTools
Added "Create Summary Multi Plot" to menu of MultiPlot in project tree
* #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