UI update

Implemented features:

- congestion show and clear (detected congestion: red circle, predicted
congestion: blue circle - certainty is indicated by opacity)
- ramp metering rate display (4 levels at the moment)
- ramp can be selected from "Ramp Metering" window
- added ramp metering rate control (lower and upper limits) - appears
when ramp is selected
- top left graph shows historical rate vs density data for the selected
ramp (mock data is displayed at the moment)
- map shows real location of ramps
- when a ramp is selected, map jumps to its location