Classification grid - faded records

Records are faded if they are not shared

This makes sense in Shariant as it's a way of highlighting that eg a discordance has stopped a record being shared.

But in systems with their own classifications - you end up fading them out by default. I guess this is a way of encouraging people to share (at least in SA Path where they can, not so much research) - this is going to cause a lot of users asking me why

Proposed fixes:
* We only fade when lab is external (this is all classifications on Shariant, and none on SA Path, as we won't see external labs non-shared)
* We use a setting `CLASSIFICATION_GRID_FADE_NON_SHARED` and only set true for Shariant