navigation bar + new layout

[juliancg24]

• instead of lots of tabs we would have a navigation bar divided this way

1. National aggregates

   • By gender
   • By education

2. Subnational aggregates

2.1 All vars

• By gender
• By education

2.2 Single var

• By gender
• By education

2.3 Heatmap

3. Definition of measures

4. Maps

• Given this new organization, the sub-tabs that are shown when user clicks on a particular measure should disappear, so that there will be only side bar + tabs with families.