Finer-grained access control for Request Signature

[pmarini-nc]

When I setup an approval workflow, I need to define the group of users (or the users themselves) that can request the approval. Thus, only those users will be able to trigger the workflow.

It makes sense to put in place the same restriction for the Request Signature action, as of now if the Docusign integration is enabled all the users have access to it.

This functionality would come naturally if signing the document would be considered one of the possible ways to approve a document.