Split out the visualizers to a separate application

[Jasper-Bekkers]

This will be a bit of a longer road map item, but to keep this crate lean I'd like to turn all our gui crates off by default.

Ideally we we structure this project like puffin. Meaning we split this project up into several creates an a loose application.

1. The core allocator
2. The egui based visualizer, ready to embed directly into apps
3. A standalone application that uses the equi library.

For this to work well need to refactor a few things, as well as add an (optional) networking layer to have the allocator connect to the viewer.

I think longer term this can set us up in a way where we could use the same visualizer and tools for CPU memory as well.