GQL API: Schema in query results may contain invalid JSON

[sergiimk]

Describe the bug

GQL API may be incorrectly escaping JSON in schema.content field

Steps To Reproduce

1. Open web UI at: https://platform.demo.kamu.dev/kamu/net.rocketpool.reth.mint-burn?tab=data
2. Execute the following query:

select
  sum(case when event_name = 'TokensMinted' then amount else amount end)
from 'kamu/net.rocketpool.reth.mint-burn'

3. Observe the error in the console

Expected ',' or '}' after property value in JSON at position 132

Current Behavior

The schema.content field looks insufficiently escaped and thus breaking JSON parsing in the UI

Expected Behavior

Query executes successfully

kamu system info

latest master

Logs

No response

Anything else?

No response

[sergiimk]

Causes kamu-data/kamu-web-ui#375