Add Playwrights locator.highlight() mode to Highlight Elements

[Snooz82]

Playwright has its own feature of highlighting for some time and our keyword should support that as well.

The style can not be changed and only one selector can be highlighted at the same time.
But it has also some advantages to our method, because now you can also scroll during highlighting.
And because one one element can be highlighted at the same time, in Presenter mode that may be an option for the future.