Refactor billing code and add error monitoring

Refactored the code that retrieves the billing customer id by renaming the function getBillingCustomerId to getCustomerId. Also, bolstered error handling: implemented exception capture in particular scenarios across multiple files. If an error occurs, it's now captured and reported to the configured provider.

pnpm-lock.yaml

@@ -1029,6 +1029,10 @@ importers:
         version: 18.2.0
 
   packages/next:
+    dependencies:
+      '@kit/monitoring':
+        specifier: workspace:*
+        version: link:../monitoring/api
     devDependencies:
       '@kit/auth':
         specifier: workspace:^