v1.2.0

• ParallelFastxParser now uses all its threads on plain gzip, single-frame zstd and from_reader inputs: one thread decompresses while the workers parse the chunks.
• process_parallel now supports ordered batch completion (requires_ordering, Ordered), calls set_thread_id and on_thread_complete once per worker thread, and on_batch_complete after each chunk.
• ParallelFastxParser::for_each_with keeps a state per worker thread and returns these states, e.g. for k-mer tables.
• ParallelFastxParser::reduce is deprecated in favor of for_each_with, since it creates a state per chunk.
• ParallelFastxParser::chunks now applies to slices, mmap, BGZF and multi-frame zstd, not only uncompressed files.