Ensure babystep_apply|undo always uses the planner

The code around these calls _requires_ that the steps are immediately
processed and/or added to the subsequent planner moves.

The only part that doesn't care about immediate insertion is the
direct user-insertion though the lcd encoder.

Firmware/Marlin_main.cpp

@@ -2722,8 +2722,7 @@ static void gcode_G28(bool home_x_axis, long home_x_value, bool home_y_axis, lon
       current_position[Z_AXIS] = st_get_position_mm(Z_AXIS);
 #endif
 
-      // Reset baby stepping to zero, if the babystepping has already been loaded before. The babystepsTodo value will be
-      // consumed during the first movements following this statement.
+      // Reset baby stepping to zero, if the babystepping has already been loaded before.
       if (home_z)
         babystep_undo();
 
@@ -5161,8 +5160,7 @@ if(eSoundMode!=e_SOUND_MODE_SILENT)
 
 		mbl.reset(); //reset mesh bed leveling
 
-					 // Reset baby stepping to zero, if the babystepping has already been loaded before. The babystepsTodo value will be
-					 // consumed during the first movements following this statement.
+		// Reset baby stepping to zero, if the babystepping has already been loaded before.
 		babystep_undo();
 
 		// Cycle through all points and probe them

Firmware/mesh_bed_calibration.cpp

@@ -3030,8 +3030,6 @@ static void shift_z(float delta)
     plan_set_z_position(current_position[Z_AXIS]);
 }
 
-#define BABYSTEP_LOADZ_BY_PLANNER
-
 // Number of baby steps applied
 static int babystepLoadZ = 0;
 
@@ -3062,20 +3060,12 @@ void babystep_load()
 void babystep_apply()
 {
     babystep_load();
-#ifdef BABYSTEP_LOADZ_BY_PLANNER
     shift_z(- float(babystepLoadZ) / float(cs.axis_steps_per_unit[Z_AXIS]));
-#else
-    babystepsTodoZadd(babystepLoadZ);
-#endif /* BABYSTEP_LOADZ_BY_PLANNER */
 }
 
 void babystep_undo()
 {
-#ifdef BABYSTEP_LOADZ_BY_PLANNER
       shift_z(float(babystepLoadZ) / float(cs.axis_steps_per_unit[Z_AXIS]));
-#else
-      babystepsTodoZsubtract(babystepLoadZ);
-#endif /* BABYSTEP_LOADZ_BY_PLANNER */
       babystepLoadZ = 0;
 }