Adding a new Primitive::Scale, similar to Primitive::Translate

[setzer22]

This is related to the following discord thread: https://discord.com/channels/628993209984614400/1044619825672110092

My current use case is to be able to create a node editor application, in which nodes are regular widgets, and the node container allows for panning and zooming. Essentially this:

From our conversation on GitHub with @tarkah, it looks like an implementation for this would be achievable via a custom widget that leverages a new Primitive::Translate feature, that would be exposed via a renderer.with_scale method, similar to how there's already a renderer.with_translation.

This widget looks like something that can be worked on from user code, but it would require this low level primitive to be implemented. As I said on discord, this is something I would like to work on, if you don't mind me asking a few questions.

Seems like a good first approach to the issue would be to handle this scaling on the CPU side, changing the code for process_primitive to keep track of the current scale level, just how it's already happening for translation.

PS: I was going to open an issue, but those seem to be reserved exclusively for bug reports, so I opened a discussion thread instead. Hope that's okay!