Allow adding nested files and folders in `Add File` and `Add Folder` modal

Nature of issue?

• Found a bug
• Existing feature enhancement
• New feature request

Feature enhancement details:

Current To add files and folders in the directories (i.e. to nest them) one has to manually click on that folder and click on the New File or New Folder button. Adding files as FolderName/FileName won't nest it in the FolderName folder and instead create a new file named FolderName/FileName in the same directory.

Proposed On entering FolderName/FileName, new file named FileName should be created in the FolderName if it is present in the currently selected node. ( Likewise while nesting folders in folders)

Points of Discussion

• What should happen if FolderName is not present under the current node? Should one implicitly create it or ask the user?

Start with the Add File and Add Folder modals and trace how entered names are handled relative to the currently selected node. Verify the behavior for existing nested folders, and resolve whether a missing intermediate folder should be created or prompt the user.