[BE] Creation of Draft-mode

[AnnaH3003]

Description

After the user initially pressed the "Send"-Button, the ticket should not be considered as finished already, but firstly be considered in a so-called draft-mode. This means no mails or something like this should be send out. The ticket is switched from draft mode to submitted mode as describe in #189. After the ticket is switched to submitted mode the email is send out and so on.

User story

1. As a user who wants to report a problem
2. I want / need to make sure that the ticket contains the information I want to convey
3. So that I am sure there is no misinformation in my ticket

Acceptance criteria

• While in draft-mode, the ticket can still be edited by the user
• tickets are only then considered fully submitted as describe above

Definition of done (DoD)

• Work products are uploaded to the Github repository and merged to the main branch
• If necessary, the bill of materials section of the planning documents is updated
• Code/feature passes suited tests
• Code is peer-reviewed
• Help documentation (README) is updated
• Fits into our architecture, where possible

DoD general criteria

• Feature has been fully implemented
• Feature has been merged into the mainline
• All acceptance criteria were met
• Product owner approved features
• All tests are passing
• Developers agreed to release