SL-10566 part the fourth

Fix water rendering causing distortion map update very frame.

Reduce binds in alpha draw pool for HUD atmo suppression (may regress HUD lighting weirdness).

Add ability to retrieve current user clip plane so it can be saved/restored around water map gen.

Leave render type masks as is after reflection map render to get detail filtering applied to distortion map again.

Re-enable occlusion in distortion map rendering.