CRAM: correct CT and MF encoding datatypes from byte to int

[jmthibault79]

Also add a test demonstrating that the old byte-based code did not cause problems because byte and int codecs are identical for the full range of the fields

Checklist

• [x] Code compiles correctly
• [x] New tests covering changes and new functionality
• [x] All tests passing
• [x] Extended the README / documentation, if necessary
• [ ] Is not backward compatible (breaks binary or source compatibility)

[codecov-io]

Codecov Report

:exclamation: No coverage uploaded for pull request base (master@019465f). Click here to learn what that means. The diff coverage is 100%.

@@            Coverage Diff             @@
##             master     #1319   +/-   ##
==========================================
  Coverage          ?   67.635%           
  Complexity        ?      8230           
==========================================
  Files             ?       562           
  Lines             ?     33617           
  Branches          ?      5642           
==========================================
  Hits              ?     22737           
  Misses            ?      8706           
  Partials          ?      2174

Impacted Files	Coverage Δ	Complexity Δ
...amtools/cram/encoding/reader/CramRecordReader.java	85.256% <ø> (ø)	26 <0> (?)
...amtools/cram/encoding/writer/CramRecordWriter.java	89.231% <ø> (ø)	26 <0> (?)
...ava/htsjdk/samtools/cram/structure/DataSeries.java	100% <100%> (ø)	8 <0> (?)
...samtools/cram/structure/CramCompressionRecord.java	92.969% <100%> (ø)	113 <2> (?)