Add a `toggle` functionality similar to `IndentBlanklineToggle`

[wimstefan]

From time to time I have to select & copy text with the mouse and I always switch off all nice decorative elements to get "plain" text for the copy process.

It's not a big thing for sure - more a "nice to have " thingie ;)

[lukas-reineke]

You can turn it off by just doing :set colorcolum= But yeah, maybe a command that toggles on and off with the old value would be nice.

[wimstefan]

Wow that was an easy one! Thanks for putting my nose into it 👍

[DanielKriz]

This workaround doesn't seem to work on virt-columns specified in plugins config (with virtcolumn = {'values'}). I tried some really dirty fix with setting char = '', but that seems to break things. This toggle feature would be really nice.

[AlexSWall]

I agree that a toggle would be nice; changing the colour doesn't prevent it being including when copying the text from the buffer via a program/selection external to vim (e.g. cursor selection from terminal, tmux copy, etc.).