Multiple fields widget should fully work in the contexual form

I ran into this months ago in #3467870 — see #3467870-16: Support `{type: array, …}` prop shapes → , which included this screenshot:

(back in September!)

Re #2. So 📌 [later phase] Support matching `{type: array, …}` prop shapes Postponed should definitely be blocked on this. We'll scope this at the widget JS functionality (controls show up, it is sortable, 'add' and 'remove' add and remove the correct things, etc), which should free up #3467870 to focus on what is attempting to be built there.

🙏 Music to my ears! 😄

Feedback addressed

• The media library e2e fail is unrelated and is addressed in this MR
• The phpstan fail is unrelated and addressed in this MR

Review findings have been addressed. The CI reds are the same unrelated ones I called out in #6

• The media library e2e fail is unrelated and is addressed in this MR
• The phpstan fail is unrelated and addressed in this MR

Adding parent Meta

Knew the tabledrag targeting in ajax.hyperscriptify.js wasn't great - adding a few attributes per @larowlan suggestion does a much better job of it.

The currently skipped-on-ci e2e tests are also passing

Given the required approvals are made, this passes tests, and there's several other issues that will benefit from the hyperscriptify and test improvements, I'm going to merge this in.

Great to see this starting to work, this unblocks initial tyoe: array support as indicated in #2! 🥳

This scope couldn't include component instance forms as there aren't props that support them yet.

Adding related 📌 Add e2e tests for multi-value textfield widget in page data form Active

FWIW this is not working as expected when there is another button on the form above the multi-value widget.

I've traced it down to issues in the client data converter w.r.t cached form state where the form state is not set to programmed - which causes Drupal to find a triggering element.

Will continue with unpicking it over there.