Add strfry policies and members-only LDAP policy

This will look up nostr pubkeys in the LDAP directory to allow or deny
publishing notes to the relay.

extras/strfry/strfry-policy.ts

@@ -0,0 +1,23 @@
+#!/bin/sh
+//bin/true; exec deno run -A "$0" "$@"
+import {
+  antiDuplicationPolicy,
+  hellthreadPolicy,
+  pipeline,
+  rateLimitPolicy,
+  readStdin,
+  writeStdout,
+} from 'https://gitlab.com/soapbox-pub/strfry-policies/-/raw/develop/mod.ts';
+
+import ldapPolicy from './ldap-policy.ts';
+
+for await (const msg of readStdin()) {
+  const result = await pipeline(msg, [
+    [hellthreadPolicy, { limit: 10 }],
+    [antiDuplicationPolicy, { ttl: 60000, minLength: 50 }],
+    [rateLimitPolicy, { whitelist: ['127.0.0.1'] }],
+    [ldapPolicy],
+  ]);
+
+  writeStdout(result);
+}