Add fpc_ProcID type and use it for all process IDs

See https://github.com/zeldaret/tp/pull/2173

src/f_pc/f_pc_manager.cpp

@@ -49,7 +49,7 @@ s32 fpcM_Delete(void* i_proc) {
 }
 
 /* 8003E3B0-8003E3D0       .text fpcM_IsCreating__FUi */
-BOOL fpcM_IsCreating(uint pID) {
+BOOL fpcM_IsCreating(fpc_ProcID pID) {
     return fpcCt_IsCreatingByID(pID);
 }