add crc32 hash function

[siviae]

Use case: I build a benthos -> clickhouse pipeline and I want to add deduplication id to the events (so, the key of an event will be the (timestamp, deduplicationId) tuple). It is perfectly fine for deduplication id it to be an integer, to save some memory. Thus, I want to be able to calculate integer hash from arbitrary byte array.

I suggest to add crc32 algorithm to bloblang hash function.