api: add events to control api requests via context

Pilz.Net/Api/ApiRequestContext.cs

@@ -0,0 +1,24 @@
+namespace Pilz.Net.Api;
+
+public class ApiRequestContext
+{
+    public bool Canceled { get; internal set; }
+    public string Route { get; set; }
+    public HttpMethod Method { get; set; }
+    public ApiMessage? Message { get; set; }
+    public ApiParameterCollection? Params { get; }
+    public IApiMessageSerializer? Serializer { get; set; }
+    public Type? ResponseMessageType { get; }
+    public HttpResponseMessage? HttpResponse { get; internal set; }
+    public object? ApiResponse { get; internal set; }
+
+    public ApiRequestContext(string route, HttpMethod method, ApiMessage? message, ApiParameterCollection? @params, IApiMessageSerializer? serializer, Type? responseMessageType)
+    {
+        Route = route;
+        Method = method;
+        Message = message;
+        Params = @params;
+        Serializer = serializer;
+        ResponseMessageType = responseMessageType;
+    }
+}