[2.0.x] Make MIN_PROBE_EDGE a general option (for electronic probes) (#10069)

Some probes don't work near the edges of the bed. This change promotes MIN_PROBE_EDGE to a general setting that applies to all probing functions.

Marlin/src/config/examples/gCreate/gMax1.5+/Configuration.h

@@ -736,6 +736,9 @@
 #define Y_PROBE_OFFSET_FROM_EXTRUDER -10    // Y offset: -front +behind [the nozzle]
 #define Z_PROBE_OFFSET_FROM_EXTRUDER -0.25  // Z offset: -below +above  [the nozzle]
 
+// Certain types of probes need to stay away from edges
+#define MIN_PROBE_EDGE 45
+
 // X and Y axis travel speed (mm/m) between probes
 #define XY_PROBE_SPEED 7500
 
@@ -974,8 +977,6 @@
   #define GRID_MAX_POINTS_X 3
   #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X
 
-  // The Z probe minimum outer margin (to validate G29 parameters).
-  #define MIN_PROBE_EDGE 10
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15
@@ -1023,7 +1024,7 @@
 
   #define MESH_EDIT_GFX_OVERLAY     // Display a graphics overlay while editing the mesh
 
-  #define MESH_INSET 45             // Mesh inset margin on print area
+  #define MESH_INSET 45             // Set Mesh bounds as an inset region of the bed
   #define GRID_MAX_POINTS_X 10      // Don't use more than 15 points per axis, implementation limited.
   #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X
 
@@ -1046,7 +1047,7 @@
   //=================================== Mesh ==================================
   //===========================================================================
 
-  #define MESH_INSET 10          // Mesh inset margin on print area
+  #define MESH_INSET 10          // Set Mesh bounds as an inset region of the bed
   #define GRID_MAX_POINTS_X 3    // Don't use more than 7 points per axis, implementation limited.
   #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X