DngOpcodes: use ROIOpcode (via DummyROIOpcode wrapper) in FixBadPixelsList
DngOpcodes: use ROIOpcode (via DummyROIOpcode wrapper) in FixBadPixelsList

Avoids duplication of the same code reading and sanitizing the rectangle.

darktable-org/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed