[Tracking]: Focused Tests 🎯

[JReinhold]

🧑‍🤝‍🧑 Who: @JReinhold, @ndelangen and @ghengeveld

This is a tracking issue for the Focused Tests 🎯 project. The purpose of this issue is to keep tracking of the overall status of the project and tasks, and plan everything around it. This project is a continuation of #29088 and is related to #29530 and #29531.

⚠️ Problem

The new Testing Module is great for running tests across all stories in the whole project, however often you are only working on a subset of stories or components, and therefore you only need to run a specific set of tests. Only running a subset of tests will be faster than running all tests all the time.

🏁 Goals

1. Users can run tests at the story, component, or directory level.
2. Other test providers/addons (eg. a11y) are also able to leverage this via a new Story Actions API

🚩 Milestones

Run individual stories

Beta Give feedback

1. we need to discuss if we're doing sibling UI or child checkboxes, and we need to figure that out fast
2. Ellipsis story dropdown menu toggle on hover #29107
   +0
   
3. Story Actions API #29101
   +0
   
4. Use Story Actions API in addon-test to run focused tests #29540
   +0
   

Nice-to-haves

Beta Give feedback

1. Addon Test: Refactor test addon to include stories automatically #29367
   addon: test bug ci:normal +3
2. Improve test progress denominator in Testing Module #29541
   +0