AWS DocumentDB Support

• Redash Version: Version: 8.0.0+b32245 (a16f551e)
• Browser/OS: Chrome / MacOS 84.0.4147.105
• How did you install Redash: Self hosted AWS AMI (ami-0b97435028ca44fcc)

As it currently stands Redash does not work with AWS DocumentDB. When you go to create your first query, it breaks with Schema refresh failed. This issue is also being talked about in the Discuss community at: https://discuss.redash.io/t/schema-refresh-failed-mongodb-datasource/4020

We know the Python source code is breaking in:

https://github.com/getredash/redash/blob/ecb9adf903842694ab01479727709064296ea029/redash/query_runner/mongodb.py#L229-L241

I am not a Python developer (Node.js) and nor do I have a Python environment setup. However, I am willing to provision a AWS DocumentDB and provide credentials and access temporarily to anybody willing to debug and work on this issue.