North America Diagnostic Labs Market Forecast to 2028 - COVID-19 Impact and Regional Analysis - By Lab Type (Single/Independent Laboratories, Hospital-Based Labs, Physician Office Labs, And Others), Testing Services [Physiological Function Testing (ECG, Echo, X-ray, Endoscopy, CT, MRI, and Others), COVID-19 Testing, General and Clinical Testing, Esoteric Testing, Specialized Testing, Non-invasive Prenatal Testing, and Others], and Revenue Source (Healthcare Plan Operators and Insurers, Out-of-Pocket, and Public System)