[246] 4MiB hash list for uploads

[giventocode]

Closes: #246

This PR includes the following:

• The block/chunk size of each item in the hash list is 4MiB.
• Introduced validation to only allow multiples of 4MiB as valid block sizes.
• The root hash is set in the blob property: md5_4mib_hashlist_root_hash
• Added bash script to generate the root hash locally /scripts/rootHash.sh

[BMurri]

For some reason I thought we were doing a hash of hashes but I see we are doing a concatenation of hashes. Not necessarily a problem, I was surprised

[giventocode]

For some reason I thought we were doing a hash of hashes but I see we are doing a concatenation of hashes. Not necessarily a problem, I was surprised

It is a hash of hashes. The source of the final hash (root hash) is a list of hashes (concatenated, without a separator) of chunks of 4MiB.

[BMurri]

For some reason I thought we were doing a hash of hashes but I see we are doing a concatenation of hashes. Not necessarily a problem, I was surprised

It is a hash of hashes. The source of the final hash (root hash) is a list of hashes (concatenated, without a separator) of chunks of 4MiB.

I missed that somehow. I see it now.