Add carrier barcode regex for USPS DataMatrix

lib/Carriers.lib.php

@@ -49,7 +49,7 @@ class Carriers {
         ],
         [
             "carrier" => "usps",
-            "pattern" => "/^\\x1D420[0-9]{5,11}\\x1D[0-9]{10,}\\x1D?$/"
+            "pattern" => "/^\\x1D?420[0-9]{5,11}\\x1D?[0-9]{10,}\\x1D?$/"
         ],
         [
             "carrier" => "usps",

lib/TrackingBarcode.lib.php

@@ -30,7 +30,7 @@ class TrackingBarcode {
     public function getCarrier(): string {
         $carrier = "";
         foreach (Carriers::CARRIER_REGEXES as $p) {
-            if (preg_match($p["pattern"], strtoupper($this->code))) {
+            if (preg_match($p["pattern"]."i", $this->code)) {
                 $carrier = $p["carrier"];
                 break;
             }