Grid Model: Crash at import for 90 mill cells

[hhgs]

Error message when importing EGRID file with about 90 mill grid cells:

Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt.
You must not let any exception whatsoever propagate through Qt code.
If that is not possible, in Qt 5 you must at least reimplement
QCoreApplication::notify() and catch all exceptions there.

A standard c++ exception that terminated ResInsight caught in RiaMain.cpp: map::at
terminate called after throwing an instance of 'std::out_of_range'
what(): map::at

[magnesj]

#5716 discuss a few actions that can be investigated.