[MM_11] Cafeteria details

• Change routing of CafeteriaHeaderCard onpressed to new Detail Page
• Create new Detail Page
• Add Map intent with selection of all installed Map apps (known by map_launcher plugin)
• Display Opening and Eating times
• Display Cafeteria Image or placeholder
• Display Cafeteria description or placeholder
• Display Cafeteria news if available
• wait for Bloc data to load before displaying it in Overview
• Change Route name
• Make model nullable
• Change waiting logic to bloc/future builder

Closes #138 (closed) Closes #288 (closed)