Add helpers for custom text in menu items (#12214)

For some features it can be useful to write custom text in a menu item. This commit provides helpers to make this easier.

Marlin/src/lcd/ultralcd.cpp

 uint16_t max_display_update_time = 0;
 millis_t next_lcd_update_ms;
 
+#if HAS_LCD_CONTRAST
+  void set_lcd_contrast(const int16_t value) {
+    lcd_contrast = constrain(value, LCD_CONTRAST_MIN, LCD_CONTRAST_MAX);
+    u8g.setContrast(lcd_contrast);
+  }
+#endif
+
 #if ENABLED(ULTIPANEL)
 
   #define DEFINE_LCD_IMPLEMENTATION_DRAWMENU_SETTING_EDIT_TYPE(_type, _name, _strFunc) \
 
   #define MENU_BACK(LABEL) MENU_ITEM(back, LABEL, 0)
 
+  #define MENU_ITEM_ADDON_START(X) \
+    if (lcdDrawUpdate && _menuLineNr == _thisItemNr - 1) { \
+      SETCURSOR(X, _lcdLineNr)
+
+  #define MENU_ITEM_ADDON_END() } (0)
+
   // Used to print static text with no visible cursor.
   // Parameters: label [, bool center [, bool invert [, char *value] ] ]
   #define STATIC_ITEM_P(LABEL, ...) do{ \
    * "Motion" > "Move Axis" submenu
    *
    */
-
-  #if IS_KINEMATIC || ENABLED(NO_MOTION_BEFORE_HOMING)
-    #define _MOVE_XYZ_ALLOWED (all_axes_homed())
-  #else
-    #define _MOVE_XYZ_ALLOWED true
-  #endif
-
   #if ENABLED(DELTA)
-    #define _MOVE_XY_ALLOWED (current_position[Z_AXIS] <= delta_clip_start_height)
     void lcd_lower_z_to_clip_height() {
       line_to_z(delta_clip_start_height);
       lcd_synchronize();
     }
-  #else
-    #define _MOVE_XY_ALLOWED true
   #endif
 
   void lcd_move_menu() {
       MENU_ITEM_EDIT(bool, MSG_LCD_SOFT_ENDSTOPS, &soft_endstops_enabled);
     #endif
 
-    if (_MOVE_XYZ_ALLOWED) {
-      if (_MOVE_XY_ALLOWED) {
+    #if IS_KINEMATIC || ENABLED(NO_MOTION_BEFORE_HOMING)
+      const bool do_move_xyz = all_axes_homed();
+    #else
+      constexpr bool do_move_xyz = true;
+    #endif
+    if (do_move_xyz) {
+      #if ENABLED(DELTA)
+        const bool do_move_xy = current_position[Z_AXIS] <= delta_clip_start_height;
+      #else
+        constexpr bool do_move_xy = true;
+      #endif
+      if (do_move_xy) {
         MENU_ITEM(submenu, MSG_MOVE_X, lcd_move_get_x_amount);
         MENU_ITEM(submenu, MSG_MOVE_Y, lcd_move_get_y_amount);
       }
 
 void lcd_reset_alert_level() { lcd_status_message_level = 0; }
 
-#if HAS_LCD_CONTRAST
-
-  void set_lcd_contrast(const int16_t value) {
-    lcd_contrast = constrain(value, LCD_CONTRAST_MIN, LCD_CONTRAST_MAX);
-    u8g.setContrast(lcd_contrast);
-  }
-
-#endif
-
 #if ENABLED(ULTIPANEL)
 
   /**

Marlin/src/lcd/ultralcd.h

     uint8_t get_ADC_keyValue();
   #endif
 
-  #if ENABLED(DOGLCD)
+  #if HAS_LCD_CONTRAST
     extern int16_t lcd_contrast;
     void set_lcd_contrast(const int16_t value);
   #endif
 
+  #if ENABLED(DOGLCD)
+    #define SETCURSOR(col, row) lcd_moveto(col * (DOG_CHAR_WIDTH), (row + 1) * row_height)
+    #define SETCURSOR_RJ(len, row) lcd_moveto(LCD_PIXEL_WIDTH - len * (DOG_CHAR_WIDTH), (row + 1) * row_height)
+  #else
+    #define SETCURSOR(col, row) lcd_moveto(col, row)
+    #define SETCURSOR_RJ(len, row) lcd_moveto(LCD_WIDTH - len, row)
+  #endif
+
   #if ENABLED(SHOW_BOOTSCREEN)
     void lcd_bootscreen();
   #endif