Flickering "[object Object]" in JoinSubmissionPane

[richardolsson]

As the data is coming in when opening the JoinSubmissionPane for the first time after refresh, there is a quick flicker of "[object Object]" in the list of fields. This is probably happening because there is a custom field of type JSON, and it's not being excluded until the field types have loaded and the pane logic realizes that it should not be included in the render (because of it's JSON type).

It can be seen by opening the pane and then skipping back in the Redux state history:

One solution would be to render nothing until the field types have loaded.

Another solution would be to initially not render fields for which the value is not a string, until the correct type and render formatting can be determined.