Interface for data transfer during adapt()
This MR adds the basic interface for data transfer during grid adaptation.
- renamed refineMesh() to adaptGrid()
- class AdaptDataTransferBase: CRTP base class for data transfer
- class AdaptDataTransferDefaultImpl: default implementation class to inherit from for implementations of data transfer
- unit test for the classes above
- buildBeforeRefine(), buildBeforeCoarsen(), coarsenMesh() functions