ENH: improved point-cell and cell-point topology methods (#2715)

- for OpenFOAM-v2212 and earlier cellPoints() were constructed
  from pointCells(), but this is slower than constructing
  pointCells() from cellPoints().

  Some of the slowness is due to allocations associated with
  cells::labels(), but a large amount of slowness is the duplicate
  point avoidance. Since this is being done for many points/cells
  at once, using a bitSet for managing the duplicates amortizes
  quickly

- now construct cellPoints() from cached pointCells(), otherwise
  construct manually (using bitSet/DynamicList for bookkeeping)

- construct pointCells() from cached cellPoints(), or cached
  pointFaces(), otherwise manually.

Code Contribution: Alon Zameret

Co-authored-by: Mark Olesen