This should avoid having to go through the object component to get access
to the shape when testing for intersections.
Refs #9842

Avoid constructing unnecessary V3Ds and exit early if a point is found
to be in a block rather than checking everyting.
Refs #9842

Avoids constant dynamic casting when checking against points & rays.
Refs #9842

Remove temporary V3D constructions.
Refs #9842

Refs #9842

Refs #9842

For hollow shapes the old approach was very inefficient. The new method
chops up the sample into discrete boxes and first samples the boxes and
then inside a box. There is also a possibility of improving it further
by first removing the boxes that are in a hollow part of the object at
the caching step but this will be done later.
Refs #9842

Refs #9842

`Stitch1DMany` would sometimes appear at the start of the history log.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

* Remove superfluous asserts
* Factor out magic numbers
* Reorder asserts for readability
* Correct some whitespace

* Add group rows button to Refl UI
* Add unit test for group rows button