Added multiple file download API

[koolgax99]

Description

Added a REST API to download multiple file of a workflow.

The endpoint for the api is /api/workflows/{id}/file-multiple/ the file list is provided in the request body in json format and it is a POST request.

Sample body: { "files": [ "pecan.xml", "workflow.R" ] }

Screenshot of the API:

Motivation and Context

This comes in handy for various researchers to download multiple files from a workflow. Earlier =, a researcher could only download a single file at a time via the /api/workflows/{id}/file/{filename}

The issue created for this feature is #2940

Review Time Estimate

• [ ] Immediately
• [x] Within one week
• [ ] When possible

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] My change requires a change to the documentation.
• [ ] My name is in the list of CITATION.cff
• [ ] I have updated the CHANGELOG.md.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[koolgax99]

@istfer can you test and review the API

[mdietze]

@koolgax99 checking to see if you had plans to address the requested changes at some point

[koolgax99]

Yes @mdietze! I'll start fixing them, was caught up with other issues.

[mdietze]

@koolgax99 just pinging you again about finishing up this PR

[mdietze]

@koolgax99 checking back in about this PR. Would be good to wrap this and your other open PRs up