[Feature Request] Allow forcing disabling of extension in v-toolbar

[mitar]

Problem to solve

Currently it seems extension for v-toolbar is displayed if extended prop is set or if there are components inside the extension slot. For me, this is problematic because I would like to force the extension to not be rendered even when it contains the components, but currently this is not possible. Setting extended prop to false does not do it because contents are there.

I use portal-vue component inside the extension, so that other components can send their contents to it. I am trying to make it so that extension is visible only when contents are being send to the portal. I know when the portal has contents (so I could switch on and off a prop on v-toolbar), but portal component itself has to be present for sending the contents to work. But if portal component is present, then, currently, extension is always rendered.

Proposed solution

I would suggest that extended prop's default value is null, which would mean that the extension is rendered if extension slot has contents. But if it is set to false, extension should not be rendered even if it contains content. If it is true, it should always be rendered, even if there is no content.