Functionality provided by `__NEOFS__NETMAP*` X-headers seems unusable and unviable about neofs-api HOT 2 CLOSED

Refs. #117 and nspcc-dev/neofs-node#234. I agree that they're almost impossible to use correctly (when to use these options? How deep can I go? How deep should I go?). I don't think these headers classify anything though, it's just a fallback of some kind.

from neofs-api.

if app needs deep-deep search, client has all (*) protocol tools for this:

1. try regular GET
2. if failed, get epoch from response and request previous network map
3. for each node from previous network map, send GET with TTL=1
4. if failed again, similarly goes into the past as much as needed

(*) almost all actually #257 (comment)

from one side, client insta sees container "unhealthiness", from the other side, he's still able to try to access the data

from neofs-api.