Implement search result comparison

[wrigleyDan]

Implementation of the search result comparison

For each query of a query set:

1. Get the results for the specified search configs
2. Calculate Jaccard@k & RBO@k
3. Store the result per query in the result comparison metrics index

Executable from the command line.

Takes a configuration file as input that specifies the query set, the result sets, the metrics to be calculated, the depth (@k) for which the metrics are to be calculated.

Do we want a new/separate index for these?