Merge branch 'feature/simplify-geometrygrid-levelindexsets' into 'master'
Simplify management of LevelIndexSet's in GeometryGrid
See merge request !594 (merged)
(cherry picked from commit 66f550fa)
9fe9371a Simplify management of LevelIndexSet's in GeometryGrid 5f4ebe53 [cleanup] Remove empty destructor.