graph/db+sqldb: implement ForEachSourceNodeChannel

In this commit, the ForEachSourceNodeChannel implementation of the
SQLStore is added. Since this is the first method of the SQLStore that
fetches channel and policy info, it also adds all the helpers that are
required to do so. These will be re-used in upcoming commits as more
"For"-type methods are added.

With this implementation, we convert the `TestForEachSourceNodeChannel`
such that it is run against SQL backends.

sqldb/sqlc/queries/graph.sql

@@ -165,6 +165,27 @@ FROM channels c
 WHERE c.scid = $1
   AND c.version = $2;
 
+-- name: GetChannelFeaturesAndExtras :many
+SELECT
+    cf.channel_id,
+    true AS is_feature,
+    cf.feature_bit AS feature_bit,
+    NULL AS extra_key,
+    NULL AS value
+FROM channel_features cf
+WHERE cf.channel_id = $1
+
+UNION ALL
+
+SELECT
+    cet.channel_id,
+    false AS is_feature,
+    0 AS feature_bit,
+    cet.type AS extra_key,
+    cet.value AS value
+FROM channel_extra_types cet
+WHERE cet.channel_id = $1;
+
 -- name: HighestSCID :one
 SELECT scid
 FROM channels
@@ -172,6 +193,55 @@ WHERE version = $1
 ORDER BY scid DESC
 LIMIT 1;
 
+-- name: ListChannelsByNodeID :many
+
+SELECT sqlc.embed(c),
+    n1.pub_key AS node1_pubkey,
+    n2.pub_key AS node2_pubkey,
+
+    -- Policy 1
+    -- TODO(elle): use sqlc.embed to embed policy structs
+    --  once this issue is resolved:
+    --  https://github.com/sqlc-dev/sqlc/issues/2997
+    cp1.id AS policy1_id,
+    cp1.node_id AS policy1_node_id,
+    cp1.version AS policy1_version,
+    cp1.timelock AS policy1_timelock,
+    cp1.fee_ppm AS policy1_fee_ppm,
+    cp1.base_fee_msat AS policy1_base_fee_msat,
+    cp1.min_htlc_msat AS policy1_min_htlc_msat,
+    cp1.max_htlc_msat AS policy1_max_htlc_msat,
+    cp1.last_update AS policy1_last_update,
+    cp1.disabled AS policy1_disabled,
+    cp1.inbound_base_fee_msat AS policy1_inbound_base_fee_msat,
+    cp1.inbound_fee_rate_milli_msat AS policy1_inbound_fee_rate_milli_msat,
+    cp1.signature AS policy1_signature,
+
+       -- Policy 2
+    cp2.id AS policy2_id,
+    cp2.node_id AS policy2_node_id,
+    cp2.version AS policy2_version,
+    cp2.timelock AS policy2_timelock,
+    cp2.fee_ppm AS policy2_fee_ppm,
+    cp2.base_fee_msat AS policy2_base_fee_msat,
+    cp2.min_htlc_msat AS policy2_min_htlc_msat,
+    cp2.max_htlc_msat AS policy2_max_htlc_msat,
+    cp2.last_update AS policy2_last_update,
+    cp2.disabled AS policy2_disabled,
+    cp2.inbound_base_fee_msat AS policy2_inbound_base_fee_msat,
+    cp2.inbound_fee_rate_milli_msat AS policy2_inbound_fee_rate_milli_msat,
+    cp2.signature AS policy2_signature
+
+FROM channels c
+    JOIN nodes n1 ON c.node_id_1 = n1.id
+    JOIN nodes n2 ON c.node_id_2 = n2.id
+    LEFT JOIN channel_policies cp1
+    ON cp1.channel_id = c.id AND cp1.node_id = c.node_id_1 AND cp1.version = c.version
+    LEFT JOIN channel_policies cp2
+    ON cp2.channel_id = c.id AND cp2.node_id = c.node_id_2 AND cp2.version = c.version
+WHERE c.version = $1
+  AND (c.node_id_1 = $2 OR c.node_id_2 = $2);
+
 /* ─────────────────────────────────────────────
    channel_features table queries
    ─────────────────────────────────────────────
@@ -237,6 +307,18 @@ INSERT INTO channel_policy_extra_types (
 )
 VALUES ($1, $2, $3);
 
+-- name: GetChannelPolicyExtraTypes :many
+SELECT
+    cp.id AS policy_id,
+    cp.channel_id,
+    cp.node_id,
+    cpet.type,
+    cpet.value
+FROM channel_policies cp
+JOIN channel_policy_extra_types cpet
+ON cp.id = cpet.channel_policy_id
+WHERE cp.id = $1 OR cp.id = $2;
+
 -- name: DeleteChannelPolicyExtraTypes :exec
 DELETE FROM channel_policy_extra_types
 WHERE channel_policy_id = $1;