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/d_ky_thunder.cpp

@@ -11,6 +11,7 @@
 #include "SSystem/SComponent/c_math.h"
 #include "d/d_com_inf_game.h"
 #include "d/d_kankyo_rain.h"
+#include "f_op/f_op_camera_mng.h"
 #include "f_op/f_op_kankyo_mng.h"
 
 #define EF_THUNDER01_BMD 0x1E