feat(frontend): Add better frontend tracing (#11244)

* add better tracing through the frontend

* extend allowed headers

* add endpoint to end the trace

* end traces correctly in backend

* end trace

* early cop-out if not tracing is enabled

* Update API version link for v447

src/frontend/lib/enums/ApiEndpoints.tsx

@@ -244,5 +244,8 @@ export enum ApiEndpoints {
   email_test = 'admin/email/test/',
   config_list = 'admin/config/',
   parameter_list = 'parameter/',
-  parameter_template_list = 'parameter/template/'
+  parameter_template_list = 'parameter/template/',
+
+  // Internal system things
+  system_internal_trace_end = 'system-internal/observability/end'
 }