[ENHANCEMENT] Get and Visualize Embeddings by span name

[mbegue-cr]

Is your feature request related to a problem? Please describe.
I'd like to get quick access to use Phoenix's awesome UMAP embedding visualization for embedding vectors from a specific span name. For example, I have a RAG application that is misbehaving. I peek at embedding vectors with span name "user-input" for a quick spot-check for outliers or mode collapse. If that passes the smell test, I could do the same with "retrieved-documents". etc. etc.

Describe the solution you'd like
Not sure the best UI/UX implementation here, but it would be nice to say, filter by a span name, and then one-click visualize all embeddings in that name space.

Describe alternatives you've considered
The only way to achieve this access and visualization currently is to query the spans to a DataFrame and then import the DataFrame as a dataset with a schema.

Additional context
This is a nice-to-have. but I think it would round out Phoenix's power in terms of complete agent observability.

[axiomofjoy]

Thanks for the note @mbegue-cr! Integrating an embeddings view is not currently on our roadmap, but it is available in the Arize SaaS platform.