[ENHANCEMENT] User awareness in traces

[stdweird]

We want to give users access to the traces they generate via a webapplication that uses llama-index.

We currently see 2 issues: a. can we inject certain data in the metadata of the spans? we were thinking eg the username. this would give us also a way to filter all spans/traces of a single user b. can we get the tracedetail with only the tracedetail? we would give the users a url like http://.../projects/UHJvabcjdDoy/traces/ebf94c5d736a5e72a47c680b7edefgb6, and have broad authentication on the the ./projects/../traces url, assuming that only the user who can guess the traceid (or gets it from our app ;) can see it. right now, this tracedetail url also load the main projects page, and is like a popup rather then a standalone page.

if a can be implemented, an url that would filter spans based on metadata would also be good, so we can filter the spans that the user generated themself.