Consider new ANSI renderer for stateful.runme/output-items

[joseeantonior]

Right now, the output is only displayed in a rendered version.

Right now, the output can not be copied over. However, having both a rendered (with color!) and a plaintext output would allow for the use of the output.

This is currently handled here: https://github.com/stateful/vscode-runme/blob/main/src/constants.ts#L9