Fix Next.js service type check and add configuration logging

[marcopiraccini]

• Fix: Changed Next.js service type check from 'next' to '@platformatic/next' to match the actual type returned by the runtime config (consistent with other types like @platformatic/service, @platformatic/composer, @platformatic/db)
• Logging: Added logging during service configuration: service name and type for all services, cache schema detection, and httpCache connection info (host, port, keyPrefix — excluding username/password) for Next.js services
• Test: Added first test covering @platformatic/next service configuration with cache

[ivan-tymoshenko]

lgtm