IFrame tab doesn't save with workspace

[joshwyatt]

Good day, thanks so much for the great extension, I'm really enjoying it.

I can typically setup my JupyterLab workspace with multiple panes and tabs and then do jupyter lab workspaces export <workspace_name> and then visit the URL for that workspace and have all the panes and tabs where I left them. However, if I have a tab opened with an iFrame loaded with your extension and export the workspace, it does not get exported, and when the exported workspace is reloaded, I need to manually open the iFrame again.

It would be nice if it was persisted in the export.

Best,