fix: Segfault when hashing regions spanning multiple MiBs

[jfng]

Problem description

Attempting to do an MD5 hash of a large region (e.g. 2 MiB, u8 data[0x200000]) crashes with a segfault.

Implementation description

In hex::plugin::hashes::hashProviderRegionWithHashLib(), hashFunction->TransformBytes() is called with an offset of 0, because it iterates over data and not the entire region.