FormTokenField, ComboboxControl: Add opt-in prop for next 40px default size

[mirka]

Part of #46741

What?

To the FormTokenField and ComboboxControl components,

• Adds a __next40pxDefaultSize prop to opt into the next 40px default size.
• Mark the __next36pxDefaultSize as deprecated, and alias to the 40px prop.

Why?

Of the components that have a __next36pxDefaultSize prop, these are the only two that don't yet have a 40px size variant available.

How?

See inline comments.

Testing Instructions

Run npm run storybook:dev. For the FormTokenField and ComboboxControl stories:

1. Toggling the control for the __next36pxDefaultSize prop should log a deprecation warning to the devtools console.
2. Setting __next36pxDefaultSize to true should change the component to the 40px size.
3. Setting __next40pxDefaultSize to true should change the component to the 40px size. (If both props are defined, the __next40pxDefaultSize prop wins.)

Screenshots or screencast

[mirka]

Extracted this into a utility function because we'll be doing this for at least 6 more components.

[mirka]

Not sure why this padding was uneven 🤷

[github-actions]

Flaky tests detected in 53b7af2.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/4864382743
📝 Reported issues:

• [Flaky Test] shouldn't conflict with server-side autosave #35176 in specs/editor/various/autosave.test.js

[chad1008]

This was a fun PR, thanks for sharing it. Very cool to see the style depractation mechanisms in action!

LGTM 🚀 🚢

[ciampo]

For the dev note, see #46741

[github-actions]

Warning: Type of PR label error

To merge this PR, it requires exactly 1 label indicating the type of PR. Other labels are optional and not being checked here.

• Type-related labels to choose from: [Type] Automated Testing, [Type] Breaking Change, [Type] Bug, [Type] Build Tooling, [Type] Code Quality, [Type] Copy, [Type] Developer Documentation, [Type] Enhancement, [Type] Experimental, [Type] Feature, [Type] New API, [Type] Task, [Type] Performance, [Type] Project Management, [Type] Regression, [Type] Security, [Type] WP Core Ticket, Backport from WordPress Core.
• Labels found: [Package] Components, has dev note.

Read more about Type labels in Gutenberg.