Figure out what to do with request tokens and documents/sync

[Frando]

I was having a look at the CLI start vs add etc - and re-noticed that we have a concept of RequestToken in iroh-bytes, which has 2 issues atm:

1. It is not supported in docs at all (i.e. if you set a request token during node startup, docs cannot exchange content)
2. with the CLI we only support creating a ticket with an embedded token for data added directly with iroh start (i.e. the old provide flow), but not for data added later with iroh add

Point 2) should be easy enough to solve by exposing ticket creation over the RPC (iroh.blobs.ticket(hash) or so). However about 1) I'm unsure. For release we should add to the notes though that sync is incompatible with --request-token

[dignifiedquire]

Closing as stale