Allows a dropdown panel to open that includes all the fields of multiple-field search, including the filter toggles.
Values entered in multi-field search should be reflected in the values shown against each field on the dropdown panel.
Typing a value in a field of the dropdown panel should update the multi-field search string to include what is typed (while it is typed).
component is already implemented in storybook
date inputs are strings for now (later they will be calendar inputs)
needs a new API endpoint
move the GWT handler code to a service
call the service from the GWT handler
call the service from the new REST API endpoint
API endpoint will re-use the code from the GWT action handler
needs to filter the textflow list on the editor app