It should be allowed for a single input pipeline to $scoreFusion or $rankFusion to include both a $search/$vectorSearch and a $score.

For example, a user may want to run a $search or $vectorSearch in a sub-pipeline, but then modify the order of that input pipeline with their own custom expression.

Our current logic should permit this, but we don't have any tests for it.

More pertinently we need to ensure that the scoreDetails that come out of these pipeline preserve the scoreDetails coming from $search/$vectorSearch and $score, as both these stages and $score set scoreDetails.

Our current scoreDetails logic probably does not support this, so well need to update our logic to support this. 

Question: how should the scoreDetails structure look if there are multiple stages that set scoreDetails in the same input pipeline. Note this same question arises when there are multiple $scores in the same input pipeline