Fixes https://github.com/payloadcms/payload/issues/9767
We allow failing a job queue task by returning `{ state: 'failed' }` from the task, instead of throwing an error. However, previously, this threw an error when trying to update the task in the database. Additionally, it was not possible to customize the error message.
This PR fixes that by letting you return `errorMessage` alongside `{ state: 'failed' }`, and by ensuring the error is transformed into proper json before saving it to the `error` column.
d53f166476