Navigating and copying from cell output of jupyter notebooks

Issue: I'd like to be able to navigate and yank from the output cells in jupyter notebooks. Currently I reach for a mouse (gasp!) whenever I want to navigate a large error message, or copy the output of a cell.

Crummy work around: open the document as a json file in a separate window, and then navigate to the corresponding section in it after resaving the jupyter notebook. This doesn't work well for tracebacks, because they have ANSI escape code coloring, and this works awkwardly for images encoded as base64 strings.

An intermediate improvement to the crummy work around might be to run a script in the background that strips out this extra stuff and just shows the cleaned output cells.

Preferred solution: Treating outputs as navigable cells that can be reached through cell-mode just like code cell. Maybe this actually should be handled by the jupternotebook vscode extension, with an option to make the output cells editable? Thoughts?

No files, tests, or entry points are identified. Start by reviewing how cell-mode navigation works in the VSCodeVim extension and how Jupyter notebook output is exposed by VS Code; define whether navigation and copying require editable outputs or can be handled without changing notebook contents.