[ENHC0010029] Add TSV support for Metadata imports

[JeffreyThiessen]

What does this PR do and why?

Adds tab-delimited csv files (.tsv) to supported file types for metadata importing.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other pull requests.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. In the web interface, go to a projects samples page and click the Import Metadata button
2. See that the Upload Sample Metadata pop up indicates that TSV files are an option
3. Click Browse... to open a file picker, and see that *.tsv files are supported
4. Select a TSV file (example: test/fixtures/files/metadata/valid.tsv) and see that the Sample ID Column drop down selector shows the parsed column headers.
5. If your TSV file matches the samples you should be able to import the metadata from the file.

PR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• [x] I have evaluated the PR acceptance checklist for this PR.

[github-actions[bot]]

Simplecov Report

Covered	Threshold
92.38%	90%