Haplotype graph efficiency improvements

[lynnjo]

Description

Reworked HaplotypeGraph for efficiency, removed coroutines

Type of change

What type of changes does your code introduce? Put an x in boxes that apply.

• [ ] CHANGE (fix or feature that would cause existing functionality to not work as expected)
• [ ] FEATURE (non-breaking change which adds functionality)
• [ ] BUGFIX (non-breaking change which fixes an issue)
• [x] ENHANCEMENT (non-breaking change which improves existing functionality)
• [ ] NONE (if none of the other choices apply. Example, tooling, build system, CI, docs, etc.)

Checklist:

• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have updated relevant documentation

Changelog entry

Please add a one-line changelog entry below. This will be copied to the changelog file during the release process.

HaplotypeGraph refactored for efficiency

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 88.40580% with 8 lines in your changes missing coverage. Please review.

Project coverage is 81.35%. Comparing base (4ff26c1) to head (24fb209). Report is 13 commits behind head on main.

Files with missing lines	Patch %	Lines
...n/kotlin/net/maizegenetics/phgv2/utils/VCFUtils.kt	76.66%	0 Missing and 7 partials :warning:
...tlin/net/maizegenetics/phgv2/api/HaplotypeGraph.kt	97.43%	0 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #230 +/- ## ========================================== - Coverage 81.41% 81.35% -0.06% ========================================== Files 81 81 Lines 5444 5466 +22 Branches 903 912 +9 ========================================== + Hits 4432 4447 +15 Misses 677 677 - Partials 335 342 +7 ```

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