Add 'Jump to ID' field

A small field should be added near the navigation controls to jump to a specific problem ID. Currently one has to manually edit the URL to do this.

Start at the navigation controls in the TypeScript UI and trace how the current problem ID is read from or reflected in the URL. Add the requested field near those controls and verify that entering a specific problem ID navigates to that problem without manual URL editing.

Written by the indexing model from the issue text.