Evidence Table, add an optional flag to sort results

[marco-brandizi]

As per #726, the UI needs that the evidence table is initially sorted (by pvalue and other sensible columns), but that sucks server resources and isn't always needed, so add this to the API, but only upon request, via an optional flag parameter.

[Arnedeklerk]

As part of this, @lawal-olaotan, please remember to review the use of an additional sort in the frontend. Rather just use backend sorter if possible...

[marco-brandizi]

This is still on its own branch, needs at least 1 unit test and to be tested with the UI. Until that, we do need that the UI initially sorts the received data, but the linked code does it in the wrong way, since it sorts the rendered table, not the data, and it sorts after the initial data (in random order) have been truncated to 100 rows.