Service Desk Automation: add more fields to the "Edit issue" action

Issue description

The Edit issue action has been improved in the other feature request JSDSERVER-4258 by adding new fields to the existing list.

However, some fields still can't be set by the Edit Issue action, such as:

• the security level field (this feature request is tracked in JSDSERVER-4235)
• the Epic Link field

Suggestion

Expand the list of available fields in the Edit Issue action by adding the Epic Link, Security Level, etc...)