Motivation:
- `Config` mixes configuration representation with decoding logic
- `Config.fromPklBinary()` does not scale as decoding gains options
(e.g., binary versions or formats)
- The decoding API is inconsistent with `ConfigEvaluator`
Changes:
- Introduce `ConfigDecoder` (with builder) and move
`Config.fromPklBinary()` logic into it
- Deprecate `Config.fromPklBinary()` methods for removal
- Add `ConfigDecoder.forKotlin()` extension function
- Update and improve tests
Result:
- Decoding is separated from `Config` and exposed via a dedicated API
- Decoding can evolve independently (e.g., adding options such as binary
versions or supporting new formats)
- Evaluation and decoding APIs follow a consistent design