### What?
Currently the `DraggableBlockPlugin` and `AddBlockHandlePlugin`
components are automatically applied to every editor. For flexibility
purposes, we want to allow these to be optionally removed when needed.
### Why?
There are scenarios where you may want to enforce certain limitations on
an editor, such as only allowing a single line of text. The draggable
block element and add block button wouldn't play nicely with this
scenario.
Previously in order to do this, you needed to use custom css to hide the
elements, which still technically allows them to be accessible to the
end-user if they removed the CSS. This implementation ensures the
handlers are properly removed when not wanted.
### How?
Add `hideDraggableBlockElement` and `hideAddBlockButton` options to the
lexical `admin` property. When these are set to `true`, the
`DraggableBlockPlugin` and `AddBlockHandlePlugin` are not rendered to
the DOM.
Addresses #13636
fdab2712c0