Update style, add menu and change chart unit

[barbara-chaves]

This PR

• Updates the style
• Adds menu with other tools links
• Changes the ranking chart legend unit

Tasks

style: https://vizzuality.atlassian.net/browse/MP-176
ranking chart: https://vizzuality.atlassian.net/browse/MP-182

[clementprdhomme]

Nice job Bárbara!

I'm adding three extra comments here:

• The page has some vertical scroll. Do you think we could remove it?
• The highlighted countries on the map are still green instead of purple
• There are some issues with the exported image:
  • The Mongabay logo and attributions to Trase are gone
  • There's some extra padding at the top of the image

Before:

After:

[clementprdhomme]

A few more comments:

• I hadn't realised that you changed the order of the dropdowns before and I don't think it's a good idea. A change of value in one of the dropdowns affects the options of the ones below. So it's important that we display first the source country, then the commodity, then the change unit and finally the year. In summary, I think you should bring back the previous order.
• Do you think you could make sure that CO2 is always displayed as CO₂? Look at this example.
• There are two React errors in components/icons/index.js because you're using the stroke-width and stroke-linecap props instead of strokeWidth and strokeLinecap.
• There is a further React error in components/header/menu/index.js due to the inert prop.
• Could you update the meta tags with the new title and description?