Better handle the named-from-author in named-from-content exception

This PR created a bit of a gap #2617 In the following example axe-core basically takes just anything that looks like an accessible name and passes it. That's not ideal. Need to investigate what the best way to handle this scenario is and have axe-core flag anything that doesn't work consistently.

```html

```

(either aria-labelledby or explicit label)
| Browser (+AT) | Link | Button
|----------------|---------------------|-----------------
| Chrome name | Goodbye mars | Goodbye mars
| NVDA + Chrome | Hello mars | Goodbye mars
| JAWS + Chrome | Hello slash | Goodbye mars
| Firefox name | Goodbye mars earth | Goodbye mars earth
| NVDA + Firefox | Hello mars | Goodbye mars
| Safari name | Goodbye mars people | Goodbye mars
| VO + Safari | Goodbye earth mars | Goodbye mars
| JAWS + IE | Hello earth people | Goodbye mars

Versions: Firefox 82, Chrome 86, Safari 14, IE11, VO (MacOS) Catalina, JAWS 2020, NVDA 2020.3