Global Neurofeedback System Market By Type (Slow Cortical Potential Neurofeedback (SCP-NF), Low-energy Neurofeedback System (LENS), and Hemoencephalographic (HEG) neurofeedback), By Application (ADHD Treatment, Clinic Use, and Non-medical), By Region and Key Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2019–2028