This commit adds support for saving and loading KmerSet and KmerSetGroup structures using TOML, YAML, and JSON formats for metadata. It includes:
- Added github.com/pelletier/go-toml/v2 dependency
- Implemented Save and Load methods for KmerSet and KmerSetGroup
- Added metadata persistence with support for multiple formats (TOML, YAML, JSON)
- Added helper functions for format detection and metadata handling
- Updated version commit hash
