Support NODE_NETWORK_LIMITED filtering by default

Summary:
The seeder supports subdomaining by a whitelist filter according to node service flags.
This patch adds NODE_NETWORK_LIMITED to that whitelist by default.

Backport of this commit: https://github.com/sipa/bitcoin-seeder/commit/002bc0bbd5bfd721d7c80d7cdd35a47165f7c1ff

Test Plan:
Run the seeder until it has hundreds or thousands of nodes crawled:

./src/seeder/bitcoin-seeder -host=seeder.status.cash -ns=localhost -mbox=thonkle@protonmail.com -port=5555

Each subdomain should return results according to the filter:
NODE_NETWORK:

dig +noall +answer @:: -p 5555 x1.seeder.status.cash

NODE_NETWORK | NODE_BLOOM:

dig +noall +answer @:: -p 5555 x5.seeder.status.cash

NODE_NETWORK_LIMITED:

dig +noall +answer @:: -p 5555 x400.seeder.status.cash

NODE_NETWORK_LIMITED | NODE_BLOOM:

dig +noall +answer @:: -p 5555 x404.seeder.status.cash

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D10390