improve GRID ensemble representation in project file

[RezaeiDoust]

Currently a very effective model is used to represent ensemble summary section in project files. same methodology should be used to address grid section when GRID ensemble and grid case groups are addressed in project file.

current implelentation of summary:

            <EnsembleFileSet>
                <PathPattern>address/model_name-*</PathPattern>
                <RealizationSubSet>0-10</RealizationSubSet>
                <GroupingMode>FMU_FOLDER_MODE</GroupingMode>
                <CreateAutoName>True </CreateAutoName>
                <NameTemplateString>$KEY1-$KEY2</NameTemplateString>
            </EnsembleFileSet>

same should be used for grid

[jonjenssen]

#13357

[magnesj]

Refactor RimEclipseCaseEnsemble to use EnsembleFileSet

Investigate RimCaseCollection and RimIdenticalGridCaseGroup for usage of EnsembleFileSet