Fetch all architecture data upfront

[kkemple]

Currently only the step of a particular architecture is grabbed at one time, this is to prevent unnecessary data transfers, however soon the ability to play through an architecture's life cycle will be needed. In order to do that all data must be prefetched from the server:

https://github.com/adrianco/spigo/blob/master/ui/js/stores/chart.js#L29-L49 https://github.com/adrianco/spigo/blob/master/ui/js/stores/chart.js#L119-L137

This would also require the UI to have some sort of "loading" state.