Revise initial descriptor upload behavior for onion services
When uploading descriptors, the hidden service needs to make sure that descriptors for different clients are not uploaded at the same time (cf. Section 1.1) which is also a limiting factor for the number of clients.
At the moment it's unclear how it should be implemented and why.
- What is the threat model here?
- How exactly descriptors should be uploaded?
- In what range delays should be set?
- How this will work along with absent delays after #20082 (moved)?