Fix T67060 EEVEE: Noise caused by disk lights

This is an issue on some drivers that might output NaN out of sqrt if the
number is infinity.

EEVEE: Micro optimize disk light

Try to never do operation twice and try to use MADD operations. Even if this
is very unlikely to make any difference, it can help compilers do some
optimization. I did not measure any difference as probes have much higher
impact on render time because of texture lookups.

Note that disk light is currently the most expensive light type so it
does not hurt to micro optimize.

Fix T62730 Overlay: Selected edit hair points highlight is incorrect

This was due to the fact the drawing code was expecting the editpoints
to be equaly spaced. Reuse the code in particle.c to output the select
mask in red color channel of the particle (which is unused in new code).

Fix T72593 Blender crashes when modifier change the material count

Instead of changing the modifiers behavior, we make sure to always use
the data->totcol instead of the ob->totcol. Also we centralize getting
this number to avoid future issues.

Fix T72593 Blender crashes when separating mesh
Fix T72017 Crash on set visibility change

Fix T54422 FluidSim: ColorRamp set position does not update the viewport

This was a missing notification because of wrong type. Also remove
the id tag as the changes are still picked up by workbench and does not
affect geometry or the particle system directly.

Fix T66699 EEVEE: Material Preview "World" option doesn't work

Just hide the button for now.

Render API: Make external engine render in linear space for the viewport

This just replace the OCIO shader by a simple image shader without
color transformation.

OCIO: Use GroupTransform to avoid doing 3 transforms instead of 2

This exposes OCIO::GroupTransform to C api to be able to chain the
display transform with a corrective transform to output display linear
colors.

For now the display code only use an exponent transform to go back to
linear but should use a ColorSpaceTransform once we have the correct
config.

Fix T69070 EEVEE: Volume shader glitch if object as axis with 0.0 scale

DRW: Remove drw_engines_draw_overlays routine

It makes no sense to have it separate now.