Consider updating diagnostic channel event names for bundled modules

https://openjs-foundation.slack.com/archives/C01QF9Q31QD/p1766166962883319 I'd like to propose that when Node.js bundles an external module that generates `diagnostic_channel` events, that those event names are differentiated from the upstream names. Consider `undici`, it generates events such as `undici:request:pending-requests` (https://undici.nodejs.org/#/docs/api/DiagnosticsChannel?id=undicirequestpending-requests). These events are emitted as-is from the Node.js bundled version of Undici, thus making it impossible to determine if the event was generated from the standalone module or the bundled module. In day-to-day usage, this is not technically a problem. I am sure we can think of other cases where it might be an issue, but my current problem is that I need to retrieve the module version for the module that generated the event. I cannot currently rely on `registerHooks` to solve this because v20 does not support it. Regardless, I just think it would be better to differentiate between upstream and bundled in event emissions for clarity.