Description of the new feature

I've mentioned this as a possibility before, but I think it's time to consider it more seriously now. The idea is that we would add the extension parameter 52 to our devices attributes report, to indicate to applications that we support copying to the clipboard with OSC 52.

I've been discussing the idea with a number of other terminal devs recently, and five have already agreed with the proposal. I'm going to continue promoting the idea with other terminals and apps, but if Windows Terminal can be persuaded to sign up, I think that would already be enough of a consensus for everyone to start using it.

Proposed technical implementation details

We need to get PR #18949 merged first, so both OpenConsole and Windows Terminal have OSC 52 support, but then it's just a simple matter of adding 52 to the string here: