Fix wrong target type in UInt16Converter (#28253)

Author: stephentoub

src/System.ComponentModel.TypeConverter/src/System/ComponentModel/UInt16Converter.cs

@@ -15,7 +15,7 @@ public class UInt16Converter : BaseNumberConverter
         /// <summary>
         /// The Type this converter is targeting (e.g. Int16, UInt32, etc.)
         /// </summary>
-        internal override Type TargetType => typeof(short);
+        internal override Type TargetType => typeof(ushort);
 
         /// <summary>
         /// Convert the given value to a string using the given radix

src/System.ComponentModel.TypeConverter/tests/UInt16ConverterTests.cs

@@ -41,5 +41,12 @@ public static void ConvertTo_WithContext()
                 },
                 UInt16ConverterTests.s_converter);
         }
+
+        [Fact]
+        public static void ConvertFrom_InvalidValue_ExceptionMessageContainsTypeName()
+        {
+            Exception e = Assert.ThrowsAny<Exception>(() => s_converter.ConvertFrom("badvalue"));
+            Assert.Contains(typeof(ushort).Name, e.Message);
+        }
     }
 }