modify updated markers during upload

[ClayBirkett]

If markers are changed (for example the alt field) then provide option to update existing protocol

fixes #6167

Checklist

• Refactoring only
• Documentation only
• Fixture update only
• Bug fix
  • The relevant issue has been closed.
  • Further work is required.
• New feature
  • Relevant tests have been created and run.
  • Data was added to the fixture
    • Data was added via a patch in /t/data/fixture/patches/.
  • User-Facing Change
    • The user manual in /docs has been updated.
  • Any new Perl has been documented using perldoc.
  • Any new JavaScript has been documented using JSDoc.
  • Any new legacy JavaScript has been moved from /js to /js/source/legacy.

[ClayBirkett]

The previous code lib/SGN/Controller/AJAX/GenotypesVCFUpload) iterates over every key in the uploaded marker's $new_marker_details hash and compares each one against the same key in the stored marker. So the fields compared are whatever keys happen to be present in the new marker data hash for each marker. Typically, for a CXGN::Genotype::Protocol marker, these would include things like chrom, pos, alt, ref, qual, filter, and info — but the code itself is field-agnostic and will compare whatever is there.

In this code I have limited it to chrom, pos, alt, ref.