Add initial EE/Bus implementations

* This commit adds a most basic CPU class that acts as a template
which we will slowly build.

* The architecture is pretty simple; the ComponentManager will create all
the seperate components (EE, VP, IOP, GS etc) as unique_ptr's since
it owns them and only it has access to them. All the other components
must pass through the manager to read/write data to memory.
To achieve this they are given a pointer to the ComponentManger in their constructor.

* For now the CPU directly accesses the bios which shouldn't
happen but will be fixed eventually when I implement generic
read/writes. The goal is to start implementing the CPU as fast as
possible in order to get to the GPU/VPU's and display something!