How to map IPC roles (ipc_a/ipc_b) to actual participant IDs?

### Have you read the Contributing Guidelines?

- [x] I have read the [Contributing Guidelines](https://github.com/facebookresearch/seamless_interaction/blob/main/CONTRIBUTING.md).

### Issue Type

Missing files or data

### Dataset Label

improvised

### Dataset Split

train

### Affected Files/Data and Issue Description

Are they simply based on the order in filelist.csv? For example,
`4:V00_S0809_I00000309_P0947,improvised,dev,0,0,1,0,0
381:V00_S0809_I00000309_P0383,improvised,dev,0,40,1,0,0`
then ipc_a = P0947, and ipc_b = P0383.
Or do they following other rules which have not been mentioned?

### Steps to Reproduce

simply run the web demo and search `:V00_S0809_I00000309`

### Additional Context

_No response_

### Self-service

- [x] I'd be willing to help investigate this data issue. Add comment