Apply #pragma once, misc cleanup (#12322)

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

Marlin/src/lcd/language/language_pl.h

@@ -19,14 +19,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#pragma once
 
 /**
  * Polish for DOGM display - includes accented characters
  */
 
-#ifndef LANGUAGE_PL_DOGM_H
-#define LANGUAGE_PL_DOGM_H
-
 #define DISPLAY_CHARSET_ISO10646_PL
 
 #define CHARSIZE 2
@@ -253,5 +251,3 @@
   #define MSG_FILAMENT_CHANGE_LOAD_1          _UxGT("Ładowanie...")
   #define MSG_FILAMENT_CHANGE_RESUME_1        _UxGT("Wznowienie...")
 #endif // LCD_HEIGHT < 4
-
-#endif  // LANGUAGE_PL_DOGM_H