This commit refactors the k-mer encoding logic to handle ambiguous bases more consistently and introduces a KmerSet type for better management of k-mer collections. The frequency filter now works with KmerSet instead of roaring bitmaps directly, and the API has been updated to support level-based frequency queries. Additionally, the commit updates the version and commit hash.
This commit introduces error handling for ambiguous DNA bases (N, R, Y, W, S, K, M, B, D, H, V) in k-mer encoding. It adds new functions IterNormalizedKmersWithErrors and EncodeNormalizedKmersWithErrors that track and encode the number of ambiguous bases in each k-mer using error markers in the top 2 bits. The commit also updates the version string to reflect the latest changes.
