Cleanup data mapper

Rename
`MeshToDiamondDualMeshDataMapper` as
`ConnectivityToDiamondDualConnectivityDataMapper`
which is correct

This data mapper is now available through the
DiamondDualConnectivityManager and is built when connectivity is
constructed

The construction of this mapper is still completely independent of the
mesh construction itself which is bad since same assumptions are made
twice...

It should be actually constructed at the same time allowing for
instance easy renumbering. This should be done soon... hopefully...