probe: Perform multi-sample averaging in ProbePointsHelper class

Now that all the callers of ProbePointsHelper take a cartesian
coordinate for the probe locations, it's possible to perform averaging
of multi-sample probes within the class.  This simplifies the callers.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/delta_calibrate.py

@@ -184,7 +184,7 @@ class DeltaCalibrate:
         for i, (z_offset, spos) in enumerate(probe_positions):
             configfile.set(section, "height%d" % (i,), z_offset)
             configfile.set(section, "height%d_pos" % (i,),
-                           "%d,%d,%d" % tuple(spos))
+                           "%.3f,%.3f,%.3f" % tuple(spos))
         # Save distance measurements
         for i, (dist, spos1, spos2) in enumerate(distances):
             configfile.set(section, "distance%d" % (i,), dist)