Code quality: Fix header guards consistency

Adds `header_guards.sh` bash script, used in CI to validate future
changes. Can be run locally to fix invalid header guards.

platform/javascript/audio_driver_javascript.h

@@ -158,4 +158,4 @@ public:
 };
 #endif
 
-#endif
+#endif // AUDIO_DRIVER_JAVASCRIPT_H

platform/javascript/export/export.h

@@ -33,4 +33,4 @@
 
 void register_javascript_exporter();
 
-#endif
+#endif // JAVASCRIPT_EXPORT_H

platform/javascript/export/export_plugin.h

@@ -144,4 +144,4 @@ public:
 	~EditorExportPlatformJavaScript();
 };
 
-#endif
+#endif // JAVASCRIPT_EXPORT_PLUGIN_H

platform/javascript/export/export_server.h

@@ -248,4 +248,4 @@ public:
 	}
 };
 
-#endif
+#endif // JAVASCRIPT_EXPORT_SERVER_H

platform/javascript/godot_audio.h

@@ -63,4 +63,4 @@ extern void godot_audio_script_start(float *p_in_buf, int p_in_size, float *p_ou
 }
 #endif
 
-#endif /* GODOT_AUDIO_H */
+#endif // GODOT_AUDIO_H

platform/javascript/godot_js.h

@@ -127,4 +127,4 @@ extern void godot_js_display_vk_hide();
 }
 #endif
 
-#endif /* GODOT_JS_H */
+#endif // GODOT_JS_H

platform/javascript/godot_webgl2.h

@@ -34,4 +34,4 @@
 #include "GLES3/gl3.h"
 #include "webgl/webgl2.h"
 
-#endif
+#endif // GODOT_WEBGL2_H

platform/javascript/http_client_javascript.h

@@ -105,4 +105,5 @@ public:
 	HTTPClientJavaScript();
 	~HTTPClientJavaScript();
 };
+
 #endif // HTTP_CLIENT_JAVASCRIPT_H

platform/javascript/os_javascript.h

@@ -107,4 +107,4 @@ public:
 	OS_JavaScript();
 };
 
-#endif
+#endif // OS_JAVASCRIPT_H