[Feat]: sp-action-menu should support customizing the internal sp-menu

[charlessuh]

Code of conduct

• I agree to follow this project's code of conduct.

Impacted component(s)

sp-action-menu

Description of the requested feature

When using sp-action-menu, there is no way to customize the internal sp-menu that is opened. Potential use cases could be specifying a max-width, or overriding a supported CSS variable.

For example, perhaps sp-action-menu could support a menu slot:

<sp-action-menu size="m">
    <span slot="label">More Actions</span>
    <sp-menu slot="menu" style="max-width: 400px; --spectrum-listitem-m-height: 50px;">
        <sp-menu-item />
    </sp-menu>
</sp-action-menu>

Mockups or screenshots

No response

Implementation notes or ideas

No response

[hunterloftis]

We should review the previous decision to remove sp-menu with @adixon-adobe

[najikahalsema]

Will be addressed by #2086