Request: Query available screens

[xkns]

It would we great if it was possible to know what screens are available without going through each ID starting at 0 until the constructor fails.

In the simplest case having a way to get a number i with j ∈ 0..=i for which it wouldn't be pointless to call Capturer::new(j).

This would for example be used in a screenshot utility program to let the user pick from a list of available screens before doing any real work.

Some more metadata to go along with that would also be great but I would see that as a bonus. E.g.:

• Screen resolution
• Screen display name / adapter name

Thanks for your time and work on this project.

[bryal]

That would definitely be useful. I may look into adding it at some point, but I'll gladly accept any PRs before then :)