O1.5 - Measure the number of connections, and consumed bandwidth, using IPv4 and IPv6

See Proposal 313: Relay IPv6 Statistics: https://gitweb.torproject.org/torspec.git/tree/proposals/313-relay-ipv6-stats.txt

The child tickets are in proposal section order, but they will probably be implemented in this order:

Pre-Implementation Bugs:

• Fix: Tor relays ignore some local bytes in their statistics
• Diagnose: ConnDirectionStatistics is off by default, but most relays report it

Dependencies:

• (None)

Implementation:

• Collect IPv6 Bandwidth Stats on Relays and Bridges
• Collect IPv6 Connection Stats on Relays
• Update Directory Spec for IPv6 Stats

Internal Testing:

• Test IPv6 Statistics using Chutney (O1.3, legacy/trac#33271 (moved))

Public Tor Network Testing:

• Test IPv6 Stats on the Tor Network

Metrics Analysis:

• Analyse and Monitor IPv6 Stats

Children:

• #33159 (closed) Write a proposal for monitoring IPv6
• #33263 (closed) Prop 313: 4. Collect IPv6 Bandwidth Stats on Relays and Bridges
• #33264 (closed) Prop 313: 5. Collect IPv6 Connection Stats on Relays
• #33201 (closed) Tor relays ignore some local bytes in their statistics
• #33265 (closed) Prop 313: 6. Update Directory Spec for IPv6 Stats
• #33617 (closed) Add a BandwidthStatistics option and consensus parameter
• #33272 (closed) Prop 313: 8.2. Test IPv6 Stats on the Tor Network
• #33273 Prop 313: 8.2. Analyse and Monitor IPv6 Stats
• #33214 (closed) ConnDirectionStatistics is off by default, but most relays report it