When a `NonMatchingChecksumException` is thrown, include the calculated hexDigests

[doulikecookiedough]

When the HashStoreConverter is being used to convert Metacat to use HashStore, some files may have NonMatchingChecksumExceptions. We want to not only throw the exception, but also be able to retrieve the checksums calculated to compare, store, etc.

To Do:

• Add new method getHexDigests() to the NonMatchingChecksumException class
• Include the checksums (hexDigests) calculated when NonMatchingChecksumException is thrown

[doulikecookiedough]

This has been completed via Feature-114: NonMatchingChecksumException hexDigests Inclusion