Better testing of specific rounds

Currently there is no verification of all of the many individual rounds stores in the json files.

Consider adding tests for all rounds:

- How they are loaded in (bodies etc.) perhaps through snapshot testing?
- The rounds themselves - max score, score for a given handicap, number of arrows etc.

This will be quite a bit of mundane work so not a priority.

Start by inventorying the round JSON files and reading the existing test structure and round-loading code. Add coverage for loading each round and checking its bodies, maximum score, handicap score, and arrow count; done means every stored round has these checks and the test suite passes.

Written by the indexing model from the issue text.