Add NavigationPathQuery

Adds NavigationPathQueryParameters objects that can be used with NavigationServer.query_path() to query a customized navigation path.

modules/navigation/godot_navigation_server.h

@@ -175,6 +175,8 @@ public:
 
 	void flush_queries();
 	virtual void process(real_t p_delta_time) override;
+
+	virtual NavigationUtilities::PathQueryResult _query_path(const NavigationUtilities::PathQueryParameters &p_parameters) const override;
 };
 
 #undef COMMAND_1