Add scenario lists to scenarios interface

This commit wires up scenarios to the scenarios
interface. It uses the scenario API to query
for a list of scenarios.

A few notes about this commit
 - styling for colleague's scenarios still needs
   to be done
 - pagination was easiest/fastest if all the scenarios
   are pulled down initially then grouped; this limits
   the number of requests made to the server and not likely
   to cause a problem with the size of the request since
   the scenario metadata is small anyways.
Update translations
Merge pull request #382 from WorldBank-Transport/feature/wire-up-scenario-list-view

Add scenario lists to scenarios interface