Allow evaluator tests to read Avro format in addition to raw Z7s.

This will make it easier to write new tests for the evaluators.

• fix existing bug where expectedMissingMetadata wasn't being propagated;
• move all tests up to use semver 0.1.0 of the binary format;
• add the allowBinaryFormat option in tests so that compact requests can be specified in addition to Z7s;
• as proof that this works, remove the *_add_Z7.json files and associated tests; use the *_add.json files instead

In a subsequent MR, we can switch all of the existing tests over, as well.