feat(test-tools): Add with-test-port command to support tinylicious real service tests

[Josmithr]

Adds with-test-port command, and updates getTestPort function so that they can be used to dynamically assign ports to tinylicious real service tests. Currently, packages that leverage these tests are required to hard-code repo-globally unique ports (in multiple locations, which must match) for their tinylicious service instances. This functionality will allow them to get their ports dynamically in a way that guarantees no conflicts between packages.

This is part of a multi-PR effort to allow our repo's tinylicious real service tests to get port assignments dynamically.

This library update needs to be published before the changes can be used in the client packages. But the whole story can be previewed here: #27701.

[github-actions]

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[github-actions]

🔗 No broken links found! ✅

Your attention to detail is admirable.

linkcheck output

1: starting server using command "npm run serve -- --no-open"
and when url "[ 'http://127.0.0.1:3000' ]" is responding with HTTP status code 200
running tests using command "npm run check-links"


> fluid-framework-website@0.0.0 serve
> docusaurus serve --no-open

[SUCCESS] Serving "build" directory at: http://localhost:3000/

> fluid-framework-website@0.0.0 check-links
> linkcheck http://localhost:3000 --skip-file skipped-urls.txt

Crawling...

Stats:
  298156 links
    1937 destination URLs
    2187 URLs ignored
       0 warnings
       0 errors