Return back explicit conversion to string

Author: nvborisenko

dotnet/src/webdriver/BiDi/Network/BytesValue.cs

@@ -29,6 +29,16 @@ public abstract record BytesValue
 {
     public static implicit operator BytesValue(string value) => new StringBytesValue(value);
     public static implicit operator BytesValue(byte[] value) => new Base64BytesValue(value);
+
+    public static explicit operator string(BytesValue value)
+    {
+        if (value is StringBytesValue stringBytesValue)
+        {
+            return stringBytesValue.Value;
+        }
+
+        throw new InvalidCastException($"Cannot cast '{value.GetType()}' to '{typeof(string)}'.");
+    }
 }
 
 public sealed record StringBytesValue(string Value) : BytesValue;