This PR is adding a new docs/4.0/examples/tests/ folder to house more complex and dense kitchen sink examples of all the supported variations of a component. Perhaps there's a better location, so I'm open to moving this in the future.
For now, I'm using this to test additional input group tweaks in hopes of fixing our rounded corner issue from #25110 (closed). I'll split those commits out after verifying what we support is functioning as intended.
