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/payment-experience/GetWebProfile.php

@@ -14,7 +14,7 @@ $createProfileResponse = require 'CreateWebProfile.php';
 try {
     // If your request is successful, the API returns a web_profile object response that contains the profile details.
     $webProfile = \PayPal\Api\WebProfile::get($createProfileResponse->getId(), $apiContext);
-} catch (\PayPal\Exception\PPConnectionException $ex) {
+} catch (\PayPal\Exception\PayPalConnectionException $ex) {
     ResultPrinter::printError("Get Web Profile", "Web Profile", $webProfile->getId(), null, $ex);
     exit(1);
 }