️🛠 - Use modules / unity builds to speed up compilation

[maxwellmattryan]

Description

The JUCE modules are compiled incredibly quickly, because they are using a C++ mechanism called unity builds. It's worth checking these out and seeing if they can apply to neuron (even though it's a comparably small library).

It was advised that you should NOT use unity builds for a module that depends directly on a JUCE module, as it would change its underlying translation unit. Instead use the same style of module-packaging that JUCE uses to speed up compilation.

Requirements

TBD