[FEATURE] Perspective - Add pixel position props for percent-mode coord container components

Most of the time I want to use percent mode for P&ID layouts and device symbols etc. however I will invariably always convert the mode to fixed in order to be able to actually work on these Views, as working with it in percent mode is basically unusable since all position units then become unusable by humans.

I don’t know if it’s feasible, but it would be super nice to be able to still work with pixels.
Consider at the moment working in Vision: by default the Windows are set to effectively “percent” mode (relative scaling) and yet we still design in pixels, components paste at the right size when copying between “percent mode” Windows, etc. It would be nice if Perspective was the same.