WIP: Make infinite list a pure component

Another MR about otimizing the operation list. Expected performance gain are this time higher.

In react Components rerender each time their parent component rerenders, or on calling this.setState (their props or state changing or not). PureComponents are just Components which are a bit more intelligent :

• the rerender if one of their prop change (with === test)
• the same with the sub-states (ie an equality check is done on each property of the state)

This MR then makes the rerender of the infinite-list only when required, which means when a new line has to be displayed.