List providers

curl --request GET \
  --url https://app.plugchoice.com/api/v3/providers \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "name": "Price Ltd",
      "websocket_url": "ws://dare.org"
    },
    {
      "name": "Koch PLC",
      "websocket_url": "wss://tromp.com"
    }
  ]
}