Re-write delivery api

[ChrOertlin]

Description

re-write of the delivery api from scratch. This has been attempted multiple times now.
A new design has been established an is worked on here: #3598

• Related user stories. Some should be addressed, ideally, taking into account the new delivery API:
  • #3432
  • #2603
  • #3339
  • #2304

implementation

#3598

[ChrOertlin]

Closing as completed