[Feature Request] Add a menu item "Internalize card from note"

`Internalize card from note` is a reverse version of `Create note from card...`, i.e. when user clicks on this menu item, the plugin should **save the content of the referenced note inside the kanban note.**

This can be useful when we drag-n-drop one or more simple notes inside a kanban stack, and later find it more convenient to better edit this card **just inside the kanban view, without having to open it in another view.**

This also makes `Create note from card...` easier to be reverted if user has changed their mind some days later after clicking on `Create note from card...`.

Start by locating the existing “Create note from card...” menu action and the code handling referenced notes in the kanban view. Define the inverse behavior so the referenced note’s content is saved inside the kanban note, and verify that the new action can reverse note creation as described.

Written by the indexing model from the issue text.