d_a_npc debug work (#2863)

* Remove d_a_npc3.cpp

This file appears to not actually be real and the asserts in its
functions all reference d_a_npc2.cpp instead.

* d_a_npc debug almost matching

src/d/actor/d_a_obj_gra2.cpp

@@ -6,7 +6,7 @@
 #include "d/dolzel_rel.h" // IWYU pragma: keep
 
 #include "d/actor/d_a_obj_gra2.h"
-#include "Z2AudioLib/Z2Instances.h"
+#include "d/actor/d_a_npc4.h"
 #include "d/actor/d_a_tag_gra.h"
 #include "d/d_bg_w.h"
 #include "d/d_cc_uty.h"
@@ -16,9 +16,8 @@
 #include "d/d_debug_viewer.h"
 #endif
 #include "d/d_msg_object.h"
-#include "d/d_attention.h"
 #include "f_op/f_op_camera_mng.h"
-#include <cmath.h>
+#include "Z2AudioLib/Z2Instances.h"
 
 class daObj_GrA_Param_c {
 public: