UX changes

By Brendan

Current / Retro picker - horizontal padding

Date section - same height for Current and Retro

Horizontal lines are missing, north of the equator

Landscape on small phone - put gratinfo section to the right of the map section

Add < and > buttons to the date, if we have multiple dates available in Current mode, for example on the weekend

Make the accent colour different in dark mode?

Make the retrohash date picker only go from first DJ open to yesterday

GratInfo section - consistent padding, top and bottom

Add OpenStreetMaps to the list of mapping apps