U.S. Retail Clinics Market Size, Share & COVID-19 Impact Analysis, By Service Type (Acute Respiratory Infections, Sore Throat, Conjunctivitis, Urinary Tract Infections, Immunization, Screening Services, and Others), By Ownership (Retailer-Owned Operators, Independent Operators, and Hospital-Owned Operators), By Channel (Retail Pharmacies, Groceries/Retail Stores, and Others), and Forecast, 2022-2029