Adding custom move feedrate for G26 (#20729)

* Adding custom move feedrate for G26

This commit adds an additional configuration parameter that can be used to specify the movement speed during the G26 validation pattern command during moves without extrusion.

Closes MarlinFirmware/Marlin#20615

* Fixing missing default 'G26_XY_FEEDRATE_MOVE' value

This commit adds a default 'G26_XY_FEEDRATE_MOVE' value (max movement speed / 1.5) in the G26.cpp - same behaviour as the default 'G26_XY_FEEDRATE' value

* Adding comment describing functionality in G26.cpp

* Renaming 'G26_XY_FEEDRATE_MOVE' to 'G26_XY_FEEDRATE_TRAVEL'

Configuration parameter renamed for better readability and consistency

MarlinFirmware/Marlin#20615

* Setting 'G26_XY_FEEDRATE_TRAVEL' to a safer value, aligned comments

Changed default value for 'G26_XY_FEEDRATE_TRAVEL' from 150 mm/s to 100 mm/s for safety purposes, comment alignment

MarlinFirmware/Marlin#20615

Marlin/Configuration.h

     #define MESH_TEST_HOTEND_TEMP  205    // (°C) Default nozzle temperature for the G26 Mesh Validation Tool.
     #define MESH_TEST_BED_TEMP      60    // (°C) Default bed temperature for the G26 Mesh Validation Tool.
     #define G26_XY_FEEDRATE         20    // (mm/s) Feedrate for XY Moves for the G26 Mesh Validation Tool.
+    #define G26_XY_FEEDRATE_TRAVEL  100   // (mm/s) Feedrate for XY Moves without extrusion for the G26 Mesh Validation Tool
     #define G26_RETRACT_MULTIPLIER   1.0  // G26 Q (retraction) used by default between mesh test elements.
   #endif
 

Marlin/src/gcode/bedlevel/G26.cpp

   #define G26_XY_FEEDRATE (PLANNER_XY_FEEDRATE() / 3.0)
 #endif
 
+#ifndef G26_XY_FEEDRATE_TRAVEL
+  #define G26_XY_FEEDRATE_TRAVEL (PLANNER_XY_FEEDRATE() / 1.5)
+#endif
+
 #if CROSSHAIRS_SIZE >= INTERSECTION_CIRCLE_RADIUS
   #error "CROSSHAIRS_SIZE must be less than INTERSECTION_CIRCLE_RADIUS."
 #endif
 
   const xy_pos_t dest = { rx, ry };
 
-  const bool has_xy_component = dest != current_position; // Check if X or Y is involved in the movement.
+  const bool has_xy_component = dest != current_position; // Check if X or Y is involved in the movement.  
+  const bool has_e_component = e_delta != 0.0;
 
   destination = current_position;
 
     destination = current_position;
   }
 
-  // If X or Y is involved do a 'normal' move. Otherwise retract/recover/hop.
+  // If X or Y in combination with E is involved do a 'normal' move. 
+  // If X or Y with no E is involved do a 'fast' move
+  // Otherwise retract/recover/hop.
   destination = dest;
   destination.e += e_delta;
-  const feedRate_t feed_value = has_xy_component ? feedRate_t(G26_XY_FEEDRATE) : planner.settings.max_feedrate_mm_s[E_AXIS] * 0.666f;
+  const feedRate_t feed_value = 
+    has_xy_component 
+    ? (has_e_component ? feedRate_t(G26_XY_FEEDRATE) : feedRate_t(G26_XY_FEEDRATE_TRAVEL)) 
+    : planner.settings.max_feedrate_mm_s[E_AXIS] * 0.666f;
   prepare_internal_move_to_destination(feed_value);
   destination = current_position;
 }