Add solution stats to PDF output

Add more information about a generated solution to PDF exports. There are two levels statistics can be shown at, which should match the information available elsewhere in the application:

- Solution level
- Show the same metrics as are shown on the Timeline view (total cost, total km driven, shipments assigned and skipped, vehicles used, route duration, etc)
- Route level
- Show information from the "Metrics per route" Table view (load limits, number of pickups and dropoffs, traveled distance, etc)