Adding Delete option for deleting draft/submitted form and xml file

[hannyle]

Proposed solution

As a continuation of PR: #811, there should be a Delete button under Options to delete a form or a XML file.

DoD (Definition of Done)

We should be able to delete form and xml file. The implementation follows the design: https://www.figma.com/proto/NJiSfMKCPMJZIduAYVq0he/SD-Submit-Prototype-2?page-id=3279%3A18679&node-id=3279%3A18811&viewport=259%2C48%2C0.14&scaling=min-zoom&starting-point-node-id=3279%3A19001

Testing

Integration tests