Adds nf-test for IRIDA Next JSON output

[sgsutcliffe]

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 pipeline conventions in the contribution docs
• [ ] If necessary, also make a PR on the nf-core/staramr branch on the nf-core/test-datasets repository.
• [x] Make sure your code lints (nf-core lint).
• [x] Ensure the test suite passes (nextflow run . -profile test,docker --outdir <OUTDIR>).
• [ ] Usage Documentation in docs/usage.md is updated.
• [ ] Output Documentation in docs/output.md is updated.
• [ ] CHANGELOG.md is updated.
• [ ] README.md is updated (including new tool citations and authors/contributors).

[sgsutcliffe]

Adding multiple genomes ended up causing some downstream issues with iridanext plugin and nf-test, because each sample generated its own summary.tsv file in its own directory, the iridanext.config was only pulling one file. We added the nf-core module csvtk and the function CSVTK_CONCAT to the the summary.tsv files. This creates a single merged_summary.tsv file that we can use for adding metadata for all the genomes in the iridianext plugin. I also had to change the names of the summary.tsv files to include their sample IDs in the name so that CSVTK_CONCAT would not throw an error in having multiple files with the same name.

[sgsutcliffe]

Right now the merged_summary.tsv seems to be unable to be added as a global file. Leaving the issue unresolved for this PR