graph/db+sqldb: impl DisabledChannelIDs

Which lets us run `TestDisabledChannelIDs` against our SQL DB backends.

sqldb/sqlc/queries/graph.sql

@@ -573,6 +573,19 @@ JOIN channel_policy_extra_types cpet
 ON cp.id = cpet.channel_policy_id
 WHERE cp.id = $1 OR cp.id = $2;
 
+-- name: GetV1DisabledSCIDs :many
+SELECT c.scid
+FROM channels c
+    JOIN channel_policies cp ON cp.channel_id = c.id
+-- NOTE: this is V1 specific since for V1, disabled is a
+-- simple, single boolean. The proposed V2 policy
+-- structure will have a more complex disabled bit vector
+-- and so the query for V2 may differ.
+WHERE cp.disabled = true
+AND c.version = 1
+GROUP BY c.scid
+HAVING COUNT(*) > 1;
+
 -- name: DeleteChannelPolicyExtraTypes :exec
 DELETE FROM channel_policy_extra_types
 WHERE channel_policy_id = $1;