Global River Cruise Market Size, Share & Demand Report By Cruise Type (Luxury River Cruises, Mid-Range River Cruises, Budget River Cruises, Boutique & Themed Cruises), By Application (Leisure Tourism, Cultural & Heritage Cruises, Culinary & Wine Cruises, Wellness Cruises, Corporate Cruises), By Traveler Type (Couples, Group Travelers, Solo Travelers, Families), By Region & Segment Forecasts, 2025–2030