🐛 UI & UX: default values are not loaded for OAuth Flow

[bazarnov]

Environment

• Airbyte version: dev
• OS Version / Instance: any
• Deployment: Docker
• Source Connector and version: no matter
• Destination Connector and version: no matter
• Severity: High/Critical
• Step where error happened: Setup new connection

Current Behavior

While setting up the connector, the UI doesn't preload the default values that are set with default parameter inside of ConnectorSpecification. As the result, we hit the error (see the video attached).

Expected Behavior

The default values coming from the ConnectorSpecification should be preloaded before the Authenticate button is pressed.

Logs

Oauth_default_values.mov

Steps to Reproduce

1. Run the DEV version of UI locally, along with DEV version of Airbyte instance.
2. Modify any of existing connectors suitable for OAuth2.0 to have the default value for the field that should be passed from Front-end to Back-end to pass the Authentication using OAuth2.0. (you can use this PR for the test as well)
3. Rebuild and change the version of the connector to be the dev in the settings.
4. Create the source connection.
5. Don't touch the field you are testing, during the connection setup.
6. Press the Authenticate button - you should see nothing happens.
7. Check the console/network for broken requests.