Components: Enforce consistent usage of Button and ToolbarGroup components

[gziolo]

Description

It also extracts some changes from #17847, cc @diegohaz:

• converts all button tag elements to Button components for consistency
• replaces all usages of Toolbar components with ToolbarGroup in core blocks

In addition, this PR introduced ESLint change which discourages usage on button tag element in all production files. The only exception is save method implementation for the block definition.

How has this been tested?

npm run test-unit
npm run lint-js

Types of changes

Refactoring

Screenshots

Before

After

No visual changes 😃

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR. .

[gziolo]

There are two issues with CSS specificity which I couldn't resolve myself:

Tabs in the sidebar still need a fix for the outline when focused:

Inserter item still needs a fix for the background color when focused and hovered:

I would appreciate some help.

[jasmussen]

Pushed a fix for the two things you mentioned.

[gziolo]

I can confirm that the inserter item was fixed. The focused tab item which isn't the selected one still looks different than in master:

This branch:

master:

the outline should be dotted.

[jasmussen]

Fixed 👍 👍

[gziolo]

Thanks @jasmussen, everything looks good now. You are my CSS superhero 🥇

[gziolo]

After rebasing with the `master I noticed one unexpected change in the UI:

[jasmussen]

I see this:

The focus rectangle is missing from the toggled state, and it could use a border radius like the others. Let me know if you need help with that.

[gziolo]

This is what I see in this branch:

Should we update the hover state?

[jasmussen]

This is a solid step forward, and one that will enable further enhancements through code simplification. The HTML/Preview isn't perfect, but that "toolbar tab" pattern deserves some thought separately. As such and from a design POV, this looks good to me.

[youknowriad]

Nice work here