CRAM tiny refactor: remove CramCompressionRecord.tagIds

[jmthibault79]

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)

[jmthibault79]

It was only used inside one method. So now it's declared there.

[codecov-io]

Codecov Report

Merging #1345 into master will increase coverage by 0.302%. The diff coverage is 100%.

@@              Coverage Diff               @@
##              master    #1345       +/-   ##
==============================================
+ Coverage     67.848%   68.15%   +0.302%     
- Complexity      8283     8449      +166     
==============================================
  Files            563      563               
  Lines          33706    34314      +608     
  Branches        5657     5821      +164     
==============================================
+ Hits           22869    23385      +516     
- Misses          8659     8732       +73     
- Partials        2178     2197       +19

Impacted Files	Coverage Δ	Complexity Δ
...samtools/cram/structure/CramCompressionRecord.java	92.969% <ø> (ø)	113 <0> (ø)	:arrow_down:
.../samtools/cram/build/CompressionHeaderFactory.java	90.11% <100%> (ø)	64 <0> (ø)	:arrow_down:
...n/java/htsjdk/samtools/cram/structure/SliceIO.java	84.524% <0%> (+1.19%)	15% <0%> (+1%)	:arrow_up:
...c/main/java/htsjdk/samtools/util/IntervalList.java	76.321% <0%> (+2.424%)	131% <0%> (+62%)	:arrow_up:
...java/htsjdk/samtools/cram/structure/Container.java	91.781% <0%> (+3.737%)	31% <0%> (+4%)	:arrow_up:
...samtools/util/AsyncBlockCompressedInputStream.java	76% <0%> (+4%)	13% <0%> (+1%)	:arrow_up:
...ain/java/htsjdk/samtools/cram/structure/Slice.java	72.174% <0%> (+4.581%)	67% <0%> (+24%)	:arrow_up:
...va/htsjdk/samtools/cram/structure/ContainerIO.java	68.056% <0%> (+4.722%)	10% <0%> (ø)	:arrow_down:
...main/java/htsjdk/variant/vcf/AbstractVCFCodec.java	79.2% <0%> (+5.354%)	145% <0%> (+59%)	:arrow_up:
src/main/java/htsjdk/samtools/util/Interval.java	66.667% <0%> (+5.376%)	43% <0%> (+15%)	:arrow_up: