d_camera improvements (part 1) (#2623)

* Rename several dCamera_c fields

* Refactor mWork to generic buffer instead of union

* d_camera match improvements

* Implement several dCamera_c functions

* Remove d_camera.h from PCH

The symbol names in d_camera indicate that this header wasn't
included in the PCH (as they're compiled directly in d_camera.cpp).

src/d/actor/d_a_obj_brg.cpp

@@ -13,6 +13,7 @@
 #include "d/actor/d_a_player.h"
 #include "d/d_path.h"
 #include "Z2AudioLib/Z2Instances.h"
+#include "f_op/f_op_camera_mng.h"
 
 /* 80BBC90C-80BBCCFC 0000EC 03F0+00 1/1 0/0 0/0 .text
  * ride_call_back__FP4dBgWP10fopAc_ac_cP10fopAc_ac_c            */