Support displaying messages of "webhooks / bots / integrations"

[nickvergessen]

• Overview issue at Webhook Support / bot integration spreed#1879
• API work at feat(bots): 🐣 Start with implementing bots spreed#9458
• Client todos
  • Possibly a new actor type will be introduced that might need to be supported properly

[nickvergessen]

Setting prio to Low until the approach is clear, although the Meta is High

[nickvergessen]

Seems to work out of the box