fix(typescript): collect coverage in ts_project

[subnova]

Fixes #2762

PR Checklist

Please check if your PR fulfills the following requirements:

Any advice on how to create a test for this appreciated.

• Tests for the changes have been added (for bug fixes / features)
• [ n/a] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [ x] Bugfix
• Feature (please, look at the "Scope of the project" section in the README.md file)
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

Coverage reports are not generated when tests are built using ts_project

Issue Number: #2762

What is the new behavior?

Coverage reports are generated

Does this PR introduce a breaking change?

• Yes
• [ x] No

Other information

[subnova]

Hi, I see there are some required checks waiting here. Is there something I need to do to trigger those?

[alexeagle]

Thanks for the ping, I'm not sure why the CircleCI didn't pick this up, but that's for coverage in actual browsers and I'm confident in this change without that.