mutationsOverTime/queriesOverTime: supply overall mutation data

[fhennig]

In the frontend we need total proportion for a mutation, so we can apply the proportion filter. We now need the same thing for the new queries.

For mutations, this is currently solved with the FetchSubstitutionsOrDeletionsOperator which calls the nucleotideMutations endpoint (and similarly for AAs). But for the new queries, we don't have an equivalent endpoint.

Something like this would be needed (property name can be different):

  {
    queries: [...],
    dateRanges: [...],
    data: [...],           // existing time-series
    totalCountsByDateRange: [...],
    overallStatisticsByQuery: [ // NEW
      { count: 100, coverage: 150, proportion: 0.67 },
      ...
    ]
  }

[fhennig]

@fengelniederhammer Hey, just bringing this to your attention. I tagged it already in the issue that you worked on, but didn't really explain it (I think we could've maybe done it at the same time as the new endpoint). But now we will need to implement this to get proportion filtering for queries. It's already prioritized, maybe if you have some time you can have a look; but just letting you know.