add n8n deployment, update pgcat with n8n pool

pgcat/configmap.yaml

@@ -64,3 +64,24 @@ data:
       ["10.100.3.185", 5432, "replica"],
       ["10.100.1.83", 5432, "replica"]
     ]
+
+    [pools.n8n]
+    pool_mode = "transaction"
+    default_role = "primary"
+    query_parser_enabled = false
+    query_parser_read_write_splitting = false
+    primary_reads_enabled = true
+    load_balancing_mode = "random"
+
+    [pools.n8n.users.0]
+    username = "n8n"
+    password = "n8n"
+    pool_size = 10
+    min_pool_size = 2
+    server_lifetime = 86400000
+
+    [pools.n8n.shards.0]
+    database = "n8n"
+    servers = [
+      ["10.100.2.5", 5432, "primary"]
+    ]