Get Semi-coupled Select form elements to work with the State API

Despite adding a bunch of additional testing the end result is fewer LOC! +341 −345

Radix / 0.x

Native / this MR

The select element is cut off in Firefox

I noticed a regression on Firefox, the select element (initial unselected state) renders to the width of the longest option in the select. I noticed it with the select element from the test module, then tested it out by adding another property that was a long string in simple/heading/heading.component.yml

Also on Firefox, if an option is selected that is wider than the width of the settings panel, it gets cut off. This also happens in 0.x though so it's not a regression, but if it ends up being a simple fix, maybe it can be addressed in this issue since the MR deals with the select already? But if we want to hold off on it until the formal designs are implemented, that's fine with me too.

But I do think the regression I mentioned at the beginning is worth addressing here.

Re #10its not yet possible to get selects to wrap on long options in FF, but it looks much better now. The Chevron being there makes it more apparent it's a deliberate truncation.

When FF supports the select style pseudos, this will look even better

Yup its much better thanks, reviewed and approved.

Ty @hooroomoo for the review

This latest change broke the possibility to select 'None' value from any select.
We got not this validation error: data must be equal to one of the allowed values

It seems like @mayur-sose raised similar concerns internally on this.

Spend some time looking at this with @bnjmnm.

We have two options:

a) Adding _none to the json schema, and then unset the _none on submission because we definitely don't want that stored.
b) Doing this client-side (on DrupalSelect or InputBehaviors).

In the drupal widget world, this happens on #element_validate, where we unset the value if _none and not required.
As we aren't triggering that on props widgets (and that's fine AFAIK), I think is less hacky to replicate that client-side. Ideally this would be contained in DrupalSelect, so looks like the less hacky of the alternatives while both look like similar efforts.

Added a handle-none-option MR with test that should address #15

Another regression from this issue is that the caret is spinning after making a selection 😅

FB is addressed as far as I can tell so I'm merging to get _none working properly again. If there's lingering bits happy to address in a followup.