Just getting to know the project, fixes compile time and runtime errors

This PR just fixes compile time and runtime errors that show up when running the project for the first time.

Adds missing dependency mapbox-gl because react-map-gl complains without it.
Removes unused dependency gl-matrix.
Removes unused dependency web-vitals (usually added by Create React App, but never used here).
Adds missing files logo192.png and logo512.png that were referenced in the manifest, but not added.
InfoPopup: adds missing default case

buskerudbyen / cycling-norway