cellCountIJK was computed based on the value of griPointDimensions. These converstion turned up during profiling. Change implementation to have cellcount as a member variable instead of being computed every time.
Improved GitHub Action to run clang-format as part of clang-tidy
* Simplify clang-tidy workflow
* Added modernize-use-using, modernize-redundant-void-arg, readability-static-accessed-through-instance
* Add nolint for libecl typedefs