Make CardReader class static (#12451)

* Make CardReader a static class
* Make CardReader flags into bitfields

Marlin/src/feature/power_loss_recovery.cpp

@@ -84,8 +84,8 @@ void PrintJobRecovery::changed() {
  */
 void PrintJobRecovery::check() {
   if (enabled) {
-    if (!card.cardOK) card.initsd();
-    if (card.cardOK) {
+    if (!card.flag.cardOK) card.initsd();
+    if (card.flag.cardOK) {
       load();
       if (!valid()) return purge();
       enqueue_and_echo_commands_P(PSTR("M1000 S"));

Marlin/src/feature/power_loss_recovery.h

@@ -68,7 +68,7 @@ typedef struct {
   char command_queue[BUFSIZE][MAX_CMD_SIZE];
 
   // SD Filename and position
-  char sd_filename[MAXPATHNAMELENGTH];
+  char sd_filename[MAXPATHNAMELENGTH + 1];
   uint32_t sdpos;
 
   // Job elapsed time