Refs #8783 Polarisation correction temp ws cleanup

I'd missed some workspaces used when performing polarisation corrections
Refs #8783 Merge remote-tracking branch 'origin' into feature/8783

Conflicts:
	Code/Mantid/scripts/Reflectometry/isis_reflectometry/convert_to_wavelength.py
Merge branch 'feature/8783_quick_cleanup' into develop