Implement warning by user ID.

[SeraphimRP]

What component of Red (cog, command, API) would you like to see improvements on?

warnings

Describe the enhancement you're suggesting.

It seems that this was once behavior for the cog a long while ago, but I would like to propose allowing warns by user ID. It would be useful to warn IDs of users who, say, violated a rule but left before any warning could be given.

Anything else?

I'm not sure how this would intersect with warn actions, I'm not sure how the cog would perform these on absent users. I would also be willing to try and take this enhancement on if that would be preferable. My current line of thought would be to replicate the member param validation from [p]warnings and ignore DMing if the member isn't present.