This adds support for templating in rank eval requests.
Relates to #20231
Problem: In it's current state the rank-eval request API forces the user to repeat complete queries for each test request. In most use cases the structure of the query to test will be stable with only parameters changing across requests, so this looks like lots of boilerplate json for something that could be expressed in a more concise way.
Uses templating/ ScriptServices to enable users to submit only one test request template and let them only specify template parameters on a per test request basis.
Christoph Büscher
Isabel Drost-Fromm