[Toolbar] Add support for `<sl-menu-button>`

[fransdeboer]

Provide a general summary of the issue here

when an sl-menu-button is added to the actions slot ofsl-panelan error is thrown

tool-bar.js:140 Unknown element type: SL-MENU-BUTTON in sl-tool-bar. Only sl-button elements are allowed.

🤔 Expected Behavior?

make it possible to add a menu button in the panel actions slot, to support this design

😯 Current Behavior

tool-bar.js:140 Unknown element type: SL-MENU-BUTTON in sl-tool-bar. Only sl-button elements are allowed.

💁 Possible Solution

No response

🖥️ Steps to Reproduce

<sl-menu-button slot="actions" size="md" variant="primary" fill="outline" aria-label="Label">
 <sl-menu-item>1</sl-menu-item>
 <sl-menu-item>2</sl-menu-item>
</sl-menu-button>

What browsers are you seeing the problem on? (only for bugs in code)

Chrome

If other, please specify.

No response

What operating system are you using?

WSL

👤 Your name

Frans de Boer

🧢 Your product/team

Magister

🎨 Your Theme(s)

Magister

[Diaan]

[jpzwarte]

Feedback from Jeremy:

• a toggle group would take up even more space and add even more buttons in the toolbar (which is already crowded)
• split-button is not applicable, since that has a default action and that is not the case here

So with that, i think we should make it possible to also put menu buttons inside the tool-bar and make it work correctly with the overflow.