File explorer only supports local content. When content exists outside the website, the user has to open a page with the external link. External links should be supported from the FileExplorer.
[x] Create headers in FileManager module
[x] Create function to combine header properties in system.json
File explorer only supports local content. When content exists outside the website, the user has to open a page with the external link. External links should be supported from the FileExplorer.