We would like to bypass FCV-gating for the rank fusion features flags in versions 8.2+ in Atlas once there are no versions of 8.0 in use that don't have the rank fusion backport (8.0.13 and earlier).

However, we cannot disable FCV-gating by default at any time because on-prem users may still be on earlier 8.0 versions and upgrading from there to a version with $rankFusion enabled without FCV-gating has known issues.

Instead, we should add a separate query knob that

1) can be set at runtime

2) is disabled by default

3) is OR'ed with every featureFlagRankFusionBasic and featureFlagRankFusionFull check

This way we can change the FCV-gating behavior in Atlas when it is safe to do so.