[Meta task] Minimal mixnet VPN PoC

[octol]

Nym VPN minimal mixnet CLI PoC

Minimal mixnet VPN PoC. Basically consisting of two components

• A simple CLI client that captures all local IP traffic and sends it over the mixnet
• IP packet routing on the exit gateway

The client optionally supports connecting to the entry gateway using wireguard

This is the meta task that keeps track of all the subtasks.

Tasks

• [x] #3725
• [x] #3869
• [x] #3903
• [x] #3937
• [x] #3987
• [x] #3991
• [x] #3938
• [x] #3990
• [x] #3939
• [x] #4129
• [x] #4179
• [x] #4178
• [x] #4184
• [x] #4185
• [x] #4130
• [x] Disable poisson rate in client
• [x] Add flag for MTU
• [x] #4219
• [x] #4218
• [x] #4259
• [ ] Sign connect requests to stop DoS loophole
• [x] Switch to 10.0.0.0/16 to allow for more than 254 clients per exit gateway.
• [ ] Make IP allocation smarter and not give up before all are allocated.
• [ ] Backpressure in client
• [ ] Backpressure in nym-ip-packet-router
• [ ] Client disconnect request, to free up IP addresses.
• [x] Allow the nym-ip-packet-router to run separately from the exit gateway
• [x] Support running IPR and NR simultaneously

Bugs

• [x] Restore routing table on Linux fails when not in wireguard mode
• [x] Throughput appears to be asymmtric
• [x] IPv6 is not captured