tauri: copy to clipboard

[Septias]

Add the capability to copy images to the clipboard

[Simon-Laux]

could you rebase it to merge into #4533?
so that the rust method can be inside of clipboard.rs and you can use the Error type in that file instead of doing the string conversion. (see https://tauri.app/develop/calling-rust/#error-handling)

[Septias]

I changed the base to target your commit so you get a nicer diff on the web view, we can first merge it to your branch actually or wait until it is merged or merge it into main afterward.

[Septias]

For testing, I have the image visible in my clipboard manager but can not paste it really. Might be Nixos though.