Exporting and importing checks does not retain "builder" state

[williamhbaker]

See also: https://community.influxdata.com/t/problem-with-import-checkthreshold/19948

When exporting a check via the CLI and then applying it later, the status of the "builder" fields is not retained. The builder fields are used by the UI to display the status of building the check - showing errors if all the necessary selections haven't been made yet. This can result in an imported check showing errors in the UI when it has been properly configured.

In order to fix this, we will likely need a server-side representation of the builder, or some way for the UI to extrapolate it from the query.