v0.5.0

• Enable direct reading/writing of files from AWS S3, using aws_sdk & tokio (sage-cloudpath crate)
• If files are read in parallel, read them in batches (currently set to num_cpus / 2) to help prevent OOM situations
• Fix bug where protein_fdr was assigned to peptide_fdr field
• Directly serialize to CSV ByteRecord, rather than going through Serde - this enables parallel serialization, which is useful for very large runs (tens of millions of spectra)
• Additional parallelization for assignment of PEP, FDR