WIP: Consolidate Edge and Cell Interpolation for Mapping Fields

Filters usually map input fields into output fields. Several patterns exists for these mappings. There are already generalized functions for mapping by permutation and averaging. However, mapping by interpolation is not yet extracted into a standalone function and filters like Clip and Contour needs to implement essentially the same thing. In addition, the field mapping code in Clip and MIR are copy paste of each other and should be extracted.