returns Result, much smaller type than before, and still allows error reporting for each chunk.
Implemented all of Summarizable trait on SizedChunkEnum, helper methods for getting common chunk data without needing to match and destructure when using.
WaveErrors enum has variants for all current error conditions, marked #[non_exhaustive]
let binrw calculate file offset while reading, save it in KnownChunk and expose via Summarizable so CLI can use that instead of its own calculations
closes #70