Enhance form design and start a library of reusable components

I've reached a state where I think we can start landing the updates I've done. Basically the idea is to reuse more code through small components which are less tied to the DOM, and allow for faster prototyping and development of new UI counterparts for features.

I'm relatively happy of the effect of the FormRow component, for instance; I am less confident in the quality of the CSS code, to be honest, but that's where review will come handy :) @nicofrand can you take a look please, and let me know if there are simpler ways to achieve what i'm doing here?