[Feature request] @axe-core/playwright relative path selectors for nested shadow dom tree

**Product**: @axe-core/playwright 4.6.0

We started using the [support for shadow dom selectors](https://github.com/dequelabs/axe-core-npm/issues/615). It is a great feature that we were looking forward to. We have a feature request how to make it even better.

Our shadow dom tree example:

**Expectation**: We would like to be able to use relative path selectors even for a nested tree. Such as:
```
axeBuilder.include([['sports-card']]);
```

**Actual**: It seems that a full node path must be specified to test a shadow tree node. Only this worked for our case:
```
axeBuilder.include([['edge-chromium-page', 'grid-view-feed', 'cs-super-container', 'cs-personalized-feed', 'cs-feed-layout', 'fluent-card[style="grid-area:slot4;contain:unset;content-visibility:visible"]']]);
```

**Motivation**: Tests start to fail if shadow dom tree structure changes on the page. Using absolute path selectors makes test owners to do extra work every time the page is re-arranged. It would save a lot of test maintenance time to use relative path selectors. Requesting to add support for relative path selectors.