- Adds tests for GameVersionConverter
- Refactors GameVersionConverter to reduce nesting
- Fixes an edge case in GameVersion deserialization in which the JsonConstructor will be invoked even if no properties match
- Adds a test for the GameVersion deserialization edge case
- Test coverage has been added for the entire class, and verbose/redundant code has been refactored
- Fixes JSON serialization: JsonConstructor requires that the ctor parameters match fields/properties of the target class.
Previously, this meant that the JSON constructor would always throw an ArgumentNullException, as `Input` was not a class property.
