When using the address update form, users should be able to opt out of receiving donation receipts. The changes that we made for cat17 should be applied to laika, too (see T223054).

Acceptance Criteria

• The checkbox for the donation receipt opt-out is moved from the bottom to the top of the form.
• An explaining sentence is added below the checkbox ("Sie können uns Ihre aktuelle Adresse auch mitteilen, wenn Sie keine Bescheinigung erhalten möchten.").
• If users opt out of receiving a donation receipt, all form fields are optional.
• Once users fill out one of the form fields, the usual validation rules apply.

Notes
Modularize (or reuse modules), if possible/reasonable.