Provide call locations for line number selection

See https://github.com/avajs/ava/issues/2473 for context.

We need to parse the test file, ideally using `typescript`. And then provide the call locations back to AVA.

This will require some changes in AVA as well.

Start by reading the linked AVA issue 2473 for the context around line number selection. Then investigate how the TypeScript test file should be parsed and how call locations can be returned to AVA, including the required AVA changes. Done means the test file is parsed and AVA receives the call locations.

Written by the indexing model from the issue text.