[WIP] spike into a better CSS architecture

The current folder structure is becoming disorganised. 

I have removed the remaining classes from base (which should be for default elements only).

Components needs to be broken down into some flavour of atoms, molecules and organisms (with less cringe-worthy names). 

Layouts could also do with being rethought out.

I'll clean it up a bit and @aduggin and I can crack on with this on Monday.

@aduggin @andrewtennison