List discovery applications

curl --request GET \
  --url https://api.fluxer.app/v1/admin/discovery/applications \
  --header 'Authorization: <api-key>'

[
  {
    "guild_id": "<string>",
    "status": "<string>",
    "description": "<string>",
    "category_type": 123,
    "applied_at": "<string>",
    "reviewed_at": "<string>",
    "review_reason": "<string>"
  }
]