CView: Update Transform.invert() to return a new matrix rather than mutate the existing one.
CView: Update Transform.invert() to return a new matrix rather than
mutate the existing one.

Fixes Halo and other bugs in FLOW.

foam-framework/foam2,jacksonic/vjlofvhjfgm,jacksonic/vjlofvhjfgm,TanayParikh/foam2,foam-framework/foam2,foam-framework/foam2,TanayParikh/foam2,TanayParikh/foam2,foam-framework/foam2,TanayParikh/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2