hs-v2: Disable version 2 service

The minimum service version is raised from 2 to 3 which effectively
disable loading or creating an onion service v2.

As for ADD_ONION, for version 2, a 551 error is returned:

  "551 Failed to add Onion Service"

Part of #40476

Signed-off-by: David Goulet <dgoulet@torproject.org>