R2 - Support more checksums for PutObject

S3, Minio support CRC32C, CRC32, SHA-1, SHA-256. It is probably worth implementing CRC32C as this is used by the minio s3 client as of Add PutObject checksums by klauspost · Pull Request #1690 · minio/minio-go · GitHub uses crc32c by default.

S3 Related documentation: New – Additional Checksum Algorithms for Amazon S3 | AWS News Blog