tabby - Trigger event for shiny rendering when tab change

[cderv]

closes #12307

• Add test for html
• Add test for revealjs

[cscheid]

Thanks! Since you're looking at tabby events, do you mind also taking a look at that plotly rerender issue? There's a comment somewhere in our issues from Andrie with a good fix.

[cderv]

This is more difficult than I though to add some test for document preview using quarto serve.

I am going to merge that for now, and I will revisit test later. This is bigger change than I though as it touches local and CI process.

I am just committing the test document, but no test currently to check them.