Performance

[luucvanderzee]

There seem to be a few performance bottlenecks. I am just jotting them down for now:

• The cloneDeep lodash function is seriously slow, we can replace this with a more performant implementation that doesn't mess with our Dates like the previous JSON.parse(JSON.stringify ... )) implementation. Or perhaps find a way to do less cloning in general?
• Creating one component per mark is super slow. We should implement a 'batch renderer', which will be activated when using vgg-map and will be in charge of rendering all the SVG that is now rendered one Mark-component at the time.
• Our proxy implementation should be crazy fast according to this article, but I am not really able to reproduce these results- the old method, where we just make a new row object, seems to be faster in our case. But for now it works OK so we can maybe return to this later.