New module: picard/splitsambynumberofreads

[Y-Pei]

PR checklist

Closes #8669

• [X] This comment contains a description of changes (with reason).
• [X] If you've fixed a bug or added code that should be tested, add tests!
• [X] If you've added a new tool - have you followed the module conventions in the contribution docs
• [X] Remove all TODO statements.
• [X] Emit the versions.yml file.
• [X] Follow the naming conventions.
• [X] Follow the parameters requirements.
• [X] Follow the input/output options guidelines.
• [X] Add a resource label
• [X] 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 <MODULE> --profile docker
    • [X] nf-core modules test <MODULE> --profile singularity
    • [x] nf-core modules test <MODULE> --profile conda

[SPPearce]

Also, can the tool work on cram files?

[Y-Pei]

Many thanks for the review and suggestions! All requested changes updated. Re-review please?

[Y-Pei]

Does the tool use the fasta index, normally cram files just take the fasta itself

Yes seems like fai is required - would fail without

[SPPearce]

Thank you, I'll stop being nitpicky now ;)