All over the everywhere

• LTN design overhaul: remove the zoomed view, simpler road labels, multiple modal filter types
• overhaul the LTN impact prediction tool: make it work on all maps, improve how before/after paths drawn, fix major bug with paths changing spuriously, add CSV export
• transform a simple case of dual carriageways into a single road with a divider lane
• workaround broken LTN partitioning in some maps
• fix color scheme when drawing LTN cells as areas
• show an icon for schools in the LTN tool