Fix some ExtUI issues (#13799)

Marlin/src/feature/bedlevel/abl/abl.cpp

 #define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
 #include "../../../core/debug_out.h"
 
+#if ENABLED(EXTENSIBLE_UI)
+  #include "../../../lcd/extensible_ui/ui_api.h"
+#endif
+
 int bilinear_grid_spacing[2], bilinear_start[2];
 float bilinear_grid_factor[2],
       z_values[GRID_MAX_POINTS_X][GRID_MAX_POINTS_Y];

Marlin/src/feature/bedlevel/bedlevel.cpp

 #define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
 #include "../../core/debug_out.h"
 
+#if ENABLED(EXTENSIBLE_UI)
+  #include "../../lcd/extensible_ui/ui_api.h"
+#endif
+
 bool leveling_is_valid() {
   return
     #if ENABLED(MESH_BED_LEVELING)

Marlin/src/feature/pause.cpp

   // Resume the print job timer if it was running
   if (print_job_timer.isPaused()) print_job_timer.start();
 
-  ui.reset_status();
+  #if HAS_LCD_MENU
+    ui.return_to_status();
+  #endif
 }
 
 #endif // ADVANCED_PAUSE_FEATURE

Marlin/src/gcode/bedlevel/M420.cpp

   #include "../../module/configuration_store.h"
 #endif
 
+#if ENABLED(EXTENSIBLE_UI)
+  #include "../../lcd/extensible_ui/ui_api.h"
+#endif
+
 //#define M420_C_USE_MEAN
 
 /**
             set_bed_leveling_enabled(false);
             // Subtract the mean from all values
             for (uint8_t x = GRID_MAX_POINTS_X; x--;)
-              for (uint8_t y = GRID_MAX_POINTS_Y; y--;)
+              for (uint8_t y = GRID_MAX_POINTS_Y; y--;) {
                 Z_VALUES(x, y) -= zmean;
+                #if ENABLED(EXTENSIBLE_UI)
+                  ExtUI::onMeshUpdate(x, y, Z_VALUES(x, y));
+                #endif
+              }
             #if ENABLED(ABL_BILINEAR_SUBDIVISION)
               bed_level_virt_interpolate();
             #endif
-            #if ENABLED(EXTENSIBLE_UI)
-              ExtUI::onMeshUpdate(x, y, Z_VALUES(x, y));
-            #endif
           }
 
         #endif

Marlin/src/gcode/bedlevel/abl/G29.cpp

 #define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
 #include "../../../core/debug_out.h"
 
+#if ENABLED(EXTENSIBLE_UI)
+  #include "../../../lcd/extensible_ui/ui_api.h"
+#endif
+
 #if ABL_GRID
   #if ENABLED(PROBE_Y_FIRST)
     #define PR_OUTER_VAR xCount

Marlin/src/gcode/bedlevel/abl/M421.cpp

 #include "../../gcode.h"
 #include "../../../feature/bedlevel/abl/abl.h"
 
+#if ENABLED(EXTENSIBLE_UI)
+  #include "../../../lcd/extensible_ui/ui_api.h"
+#endif
+
 /**
  * M421: Set a single Mesh Bed Leveling Z coordinate
  *

Marlin/src/lcd/extensible_ui/ui_api.cpp

     #if HAS_MESH
       bool getMeshValid() { return leveling_is_valid(); }
       bed_mesh_t getMeshArray() { return Z_VALUES_ARR; }
+      float getMeshPoint(const uint8_t xpos, const uint8_t ypos) { return Z_VALUES(xpos,ypos); }
       void setMeshPoint(const uint8_t xpos, const uint8_t ypos, const float zoff) {
         if (WITHIN(xpos, 0, GRID_MAX_POINTS_X) && WITHIN(ypos, 0, GRID_MAX_POINTS_Y)) {
           Z_VALUES(xpos, ypos) = zoff;
     enqueue_and_echo_commands_P(gcode);
   }
 
+  bool commandsInQueue() { return (planner.movesplanned() || commands_in_queue); }
+  
   bool isAxisPositionKnown(const axis_t axis) {
     return TEST(axis_known_position, axis);
   }
 
+  bool isPositionKnown() { return all_axes_known(); }
+  bool isMachineHomed() { return all_axes_homed(); }
+
   PGM_P getFirmwareName_str() {
     static const char firmware_name[] PROGMEM = "Marlin " SHORT_BUILD_VERSION;
     return firmware_name;

Marlin/src/lcd/extensible_ui/ui_api.h

 
   bool isMoving();
   bool isAxisPositionKnown(const axis_t);
+  bool isPositionKnown(); // Axis position guaranteed, steppers active since homing
+  bool isMachineHomed(); // Axis position most likely correct, steppers may have deactivated
   bool canMove(const axis_t);
   bool canMove(const extruder_t);
   void enqueueCommands_P(PGM_P const);
+  bool commandsInQueue();
 
   /**
    * Getters and setters
     bool getLevelingActive();
     void setLevelingActive(const bool);
     #if HAS_MESH
+      #include "../../feature/bedlevel/bedlevel.h"
       bool getMeshValid();
       bed_mesh_t getMeshArray();
+      float getMeshPoint(const uint8_t xpos, const uint8_t ypos);
       void setMeshPoint(const uint8_t xpos, const uint8_t ypos, const float zval);
       void onMeshUpdate(const uint8_t xpos, const uint8_t ypos, const float zval);
     #endif

Marlin/src/lcd/ultralcd.cpp

 // These displays all share the MarlinUI class
 #if HAS_SPI_LCD || EITHER(MALYAN_LCD, EXTENSIBLE_UI)
   #include "ultralcd.h"
+  #include "fontutils.h"
   MarlinUI ui;
   #include "../sd/cardreader.h"
   #if ENABLED(EXTENSIBLE_UI)