⚡️ Improve Sensorless homing/probing for G28, G33 (#21899)

Marlin/src/module/probe.h

@@ -56,6 +56,11 @@
 class Probe {
 public:
 
+  #if ENABLED(SENSORLESS_PROBING)
+    typedef struct { bool x:1, y:1, z:1; } sense_bool_t;
+    static sense_bool_t test_sensitivity;
+  #endif
+
   #if HAS_BED_PROBE
 
     static xyz_pos_t offset;
@@ -256,6 +261,13 @@ public:
     static bool tare();
   #endif
 
+  // Basic functions for Sensorless Homing and Probing
+  #if EITHER(SENSORLESS_HOMING, SENSORLESS_PROBING)
+    static void enable_stallguard_diag1();
+    static void disable_stallguard_diag1();
+    static void set_homing_current(const bool onoff);
+  #endif
+
 private:
   static bool probe_down_to_z(const_float_t z, const_feedRate_t fr_mm_s);
   static void do_z_raise(const float z_raise);