Event Trigger Transformations Configure Request Body Error

### Version Information

Server Version:
v2.0.9

### Environment

CLI and graphql engine v2.1.1 running on docker

### What is the expected behaviour?

I don't want Hasura CLI to show an error when body response is valid

### Keywords

Event trigger, body response, Error during validation: [object Object]

### What is the current behaviour?

Event trigger body response show an error **"Error during validation: [object Object]"** when body response is valid

### How to reproduce the issue?

1. create or edit an event trigger
2. click on "+ Add Payload Transformation"
3. add valid webhook url
4. Edit "Configure Request Body" to any valid response body. This always throws an error

### Screenshots or Screencast

Reproduce the issue in the event trigger editor by opening “Add Payload Transformation” and editing “Configure Request Body” with a valid body. Start by tracing the TypeScript UI validation entry point for that field; done means valid request bodies no longer display “Error during validation: [object Object]”.

Written by the indexing model from the issue text.