Add support for presupplied annotation files (FAA + GFF or FAA + GBK)

[jfy133]

PR checklist

• [ ] 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!
• [ ] If you've added a new tool - have you followed the pipeline conventions in the contribution docs
• [x] If necessary, also make a PR on the nf-core/funcscan 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>).
• [x] Usage Documentation in docs/usage.md is updated.
• [ ] Output Documentation in docs/output.md is updated.
• [x] CHANGELOG.md is updated.
• [ ] README.md is updated (including new tool citations and authors/contributors).