Add HDL h2 module

[lyh970817]

HDL estimates SNP heritability and pairwise genetic correlation from GWAS summary statistics. This PR upstreams hdl/h2, which estimates SNP heritability from canonicalized GWAS summary statistics with an HDL LD reference panel.

The HDL fixtures used by these tests are available on the merged nf-core/test-datasets modules branch from nf-core/test-datasets#1932.

PR checklist

• This comment contains a description of changes (with reason).
• If you've fixed a bug or added code that should be tested, add tests!
• If you've added a new tool - have you followed the module conventions in the contribution docs
• If necessary, include test data in your PR.
• Remove all TODO statements.
• Broadcast software version numbers to topic: versions - See version_topics
• Follow the naming conventions.
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• Add a resource label
• Use BioConda and BioContainers if possible to fulfil software requirements.
• Ensure that the test works with either Docker / Singularity. Conda CI tests can be quite flaky:
  • For modules:
    • nf-core modules test hdl/h2 --profile docker
    • nf-core modules test hdl/h2 --profile singularity
    • nf-core modules test hdl/h2 --profile conda