Roles in signee list

### Description

Show roles in signee list.

Questions:
1. What should happen when a person with one or more roles (specified in the signee list) signs?
Should the person sign for all roles they have? Should they choose a role?
2. How to map roles with signature document?
Do we have to update what is stored in the signature document?
3. Should the roles be shown in the table just like org and person, or should they be listed under the table and show up in the table when signed?

### Additional Information

_No response_

Start by reviewing the existing signee list and signature document behavior, then resolve the three open questions about selecting roles, mapping them into the signature document, and displaying them. The issue does not name files, tests, or an entry point, so the work is not ready to begin until the expected behavior and completion criteria are decided.

Written by the indexing model from the issue text.