DO NOT MERGE: CRAM improve test coverage and fix a few bugs

[jmthibault79]

Add tests to improve test coverage and find bugs.

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

Merging #1306 into master will increase coverage by 0.15%. The diff coverage is 84.127%.

@@              Coverage Diff               @@
##              master     #1306      +/-   ##
==============================================
+ Coverage     67.848%   67.998%   +0.15%     
- Complexity      8273      8298      +25     
==============================================
  Files            562       562              
  Lines          33678     33689      +11     
  Branches        5653      5653              
==============================================
+ Hits           22850     22908      +58     
+ Misses          8653      8619      -34     
+ Partials        2175      2162      -13

Impacted Files	Coverage Δ	Complexity Δ
...mtools/cram/build/CramContainerHeaderIterator.java	100% <100%> (ø)	2 <1> (ø)	:arrow_down:
src/main/java/htsjdk/samtools/CRAMFileReader.java	76.02% <100%> (ø)	53 <0> (ø)	:arrow_down:
...htsjdk/samtools/cram/io/DefaultBitInputStream.java	49.275% <50%> (+10.814%)	13 <0> (+3)	:arrow_up:
...jdk/samtools/cram/structure/ContainerHeaderIO.java	74.545% <60%> (ø)	7 <0> (ø)	:arrow_down:
...ava/htsjdk/samtools/cram/structure/CramHeader.java	66.667% <85.714%> (+18.667%)	11 <6> (+4)	:arrow_up:
...va/htsjdk/samtools/cram/structure/ContainerIO.java	65.079% <87.5%> (+1.145%)	10 <5> (ø)	:arrow_down:
...c/main/java/htsjdk/samtools/cram/build/CramIO.java	83.459% <88.235%> (+8.116%)	19 <6> (-1)	:arrow_down:
...java/htsjdk/samtools/cram/common/CramVersions.java	88.235% <92.308%> (+13.235%)	6 <5> (+5)	:arrow_up:
...va/htsjdk/samtools/cram/structure/block/Block.java	81.159% <0%> (+5.797%)	25% <0%> (+2%)	:arrow_up:
... and 2 more

[cmnbroad]

Temporarily reopening this to keep it on my radar and so I can mine it for CRAM refactoring.

[cmnbroad]

I don't see any way to convert it to draft though.

[cmnbroad]

Obsoleted by https://github.com/samtools/htsjdk/pull/1440.