[skip changelog]feat: p2p: environment variables for disabling DHT query filter and routing table filter

[hanabi1224]

Related Issues

ChainSafe/forest#4576
ChainSafe/forest#4580
ChainSafe/forest#4581

Proposed Changes

We're setting up local and CI regression tests for Forest bootstrap node to make sure the Kademlia setup works for Lotus. In both test scenarios the bootstrap node has no public IP, and we need to disable the DHT PublicRoutingTableFilter in Lotus. This PR introduces environment variables for doing that.

(Skipping changelog as this is more of a developer-facing feature)

Additional Info

Checklist

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[BigLep]

Is there a corresponding docs change needed with this so users know about this toggle?

[rvagg]

I'm not sure we have a good place to put such things; we don't expect much use of this beyond what ChainSafe are doing.

git grep .Getenv.*LOTUS | awk -F'"' '{print $2}' | sort | uniq shows 38 such environment variables, most not documented anywhere.

I think it's OK to treat this as a secret little dev backdoor to an bit of functionality most people will never need.