Rework CMake configuration

[kylestach]

Description

Rework CMake configuration and directory structure. This should speed up incremental builds, as we no longer need to relink the entirety of soccer (and what was previously the robocup.so library) for any change to any of the node.

While we're at it, might as well move soccer/src/soccer -> soccer so we don't have to deal with an extra layer of nested directories for no reason.

Associated Issue

N/A, I was just annoyed

Design Documents

N/A

Steps to test

Do it build?

1. Do it build?

Expected result: It do build.

[hdemusg]

After fixing things on my side, the sim opened. I assume this is what was desired?

[kylestach]

I'll merge after comp