Renaming Namespaces and Organizing Classes

- Updated OpenId classes to be in API namespace
- Updated PP Naming Convention to PayPal Naming Convention
- FormatConverter Class got its own namespace
- Handlers are grouped in Handler namespace
- Samples and Tests Updated Accordingly

sample/notifications/createWebhook.php

@@ -54,7 +54,7 @@ try {
     $output = $webhook->create($apiContext);
 } catch (Exception $ex) {
     // ^ Ignore workflow code segment
-    if ($ex instanceof \PayPal\Exception\PPConnectionException) {
+    if ($ex instanceof \PayPal\Exception\PayPalConnectionException) {
         $data = $ex->getData();
         ResultPrinter::printError("Created Webhook Failed. Checking if it is Webhook Number Limit Exceeded. Trying to delete all existing webhooks", "Webhook", "Please Use <a style='color: red;' href='DeleteAllWebhooks.php' >Delete All Webhooks</a> Sample to delete all existing webhooks in sample", $request, $ex);
         if (strpos($data,'WEBHOOK_NUMBER_LIMIT_EXCEEDED') !== false) {