Issue Summary

Append value is an option currently available on the original workflow editor. This feature cannot be setup using the new workflow editor thereby preventing users from setting up append options for fields via the new workflow editor. 

Steps to Reproduce

1. On the old workflow editor, for different field types  [select list (multiple choices), checkboxes] etc, we have the option to append values. 
   

1. Attempt to replicate the same on the new workflow editor.

Expected Results

Able to append values on the new workflow editor.

Actual Results

Unable to append the values on the new workflow editor.

Workaround

Use old workflow editor to append values.