[Feature Request] Add ability to rename columns/w Undo from the ColumnSheet

[frosencrantz]

Context: https://github.com/saulpw/visidata/discussions/1134

Visidata now has a clean_names options which is similar to the normcol plugin. In the thread, Saul points out a way to revert the column renames after doing some work on a sheet. This would be a useful feature for this plugin.

[jsvine]

Thanks for the note, @frosencrantz — I can see that being useful. Not sure when I'll have the time to implement/test/etc., but it's now on my list. I suppose it'll need a longname. The current main command is normalize-col-names, so the reversion might be revert-normalize-col-names or undo-normalize-col-names?

[frosencrantz]

I don't have a strong opinion, but between those undo-normalize-col-names seems more consistent with the general undo commands.