[admin-ui] Add support for viewing chat sessions across all channels in a workspace

[bdb-dd]

Description

Previously, all chats were centralized to one or two channels in each workspace. Now, assistant replies are distributed across multiple direct message "channels". Adding support for a wildcard channel should be enough to get realtime updates across all channels.

Be sure to display the channel (or user) name in the ChatMessage view

Additional Information

No response