Add getUUIDForFullName method in NameManager

The getUUIDForFullName method was added in the NameManager class to retrieve the UUID for the given full name. The function retrieves the corresponding UUID from the fullNamesToUUID map after converting the provided name to lowercase.

src/main/java/com/Acrobot/ChestShop/UUIDs/NameManager.java

@@ -42,6 +42,10 @@ public static String getNameFor(Player player) {
         return currentShortName.get(player.getUniqueId());
     }
 
+    public static UUID getUUIDForFullName(String name) {
+        return fullNamesToUUID.get(name.toLowerCase());
+    }
+
     public static UUID getUUIDFor(String shortName) {
         if (Properties.ADMIN_SHOP_NAME.equalsIgnoreCase(shortName)) {
             return adminShopUUID;