Implement new design of tools page

[sebil]

What's new:

• Stage is blue again and have a animated visual element, similar to the format pages
• Format filter bubbles are more like roadmap filter bubbles
  • No 'all/none' filter for not filtered state
  • Bubbles itself could be toggled on/off
• Format tag on teaser-cards move to the bottom of card
  • These also get filter functionality
• AMP logo of official tools are placed on image with a shape as background
• Lots of design improvements (fonts, spacing, shadows, etc.)

Screenshots desktop and mobile:

[pbakaus]

Looks good, thanks! I miss the subtle "developer" grid in the header slightly, but that's a matter of taste :) This works as well.