This adds a `Clone Document` action to the context menu for documents in the explorer view. This menu is shown when a document is right clicked. So far the actions we have there are `View Document`, `Copy Document`, `Clone Document`, and `Delete Document`. I'm thinking we can probably expand the section on Documents here: https://www.mongodb.com/docs/mongodb-vscode/databases-collections/ to include the actions folks can do after right clicking a document (maybe something similar to what we have for right-clicking a collection) Thanks!