[Frontend Migration]: Update API endpoint /api/channel/{channel_id}/ add missing key "aggs"

[MerlinScheurer]

Domain

Backend

Description

Problem

"aggs" is missing missing in /api/channel/{channel_id}/, but is provided to the template view.

Solution

Add aggs to /api/channel/{channel_id}/

"aggs": {
  "total_items": { "value": 0 },
  "total_duration": { "value_str": "" },
  "total_size": { "value": "" }
}