Remove feature to link order to existing ticket

[Vince-janv]

As a developer,
I want to remove the existing ticket logic when ordering,
So that we don't have to maintain that logic in the already complex order logc

Work impact

Answer the following questions:

• Is there currently a workaround for this issue? If so, what is it?
  • N/A
• How much time would be saved by implementing this feature on a weekly basis?
  • Aggregate gains everytime we need to touch the ordering logic
• How many users are affected by this issue?
  • back-end devs
• Are customers affected by this issue?
  • No

Acceptance Criteria

• The FE option to connect to a ticket is removed
• All logic pertaining to the existing ticket linking is removed
  ...

Notes

• This feature was used regularly by one customer and very sporadically for some research projects
• @AnnaZetterlund has communicated with the customer to use our normal ordering flow 🙏

[diitaz93]

Technical refinement

FE

• Remove the checkbox in the order portal

BE

• Remove the logic regarding connect to ticket in the OrdersAPI
• Remove the extra validation in the orders endpoint

[ahdamin]

BE and FE PRs are ready. @diitaz93 Feel free to merge!