Add a registration_behavior column to AllocationToken (#1695)

This is, as of now, unused but we can use it for b/237683906 and
b/237800445 in the future to allow for special behavior dictated by
allocation tokens rather than having to reserve specific domains.

Note that we enforce a tied domain for ANCHOR_TENANT tokens (because
they should be matched to a domain) but not for BYPASS_TLD_STATE tokens.

db/src/main/resources/sql/schema/db-schema.sql.generated

@@ -24,6 +24,7 @@
         domain_name text,
         redemption_domain_history_id int8,
         redemption_domain_repo_id text,
+        registration_behavior text not null,
         renewal_price_behavior text not null,
         token_status_transitions hstore,
         token_type text,