feat: add updated_by to tracker tables (#2604)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

crates/common_enums/src/enums.rs

@@ -809,6 +809,29 @@ pub enum EventType {
     MandateRevoked,
 }
 
+// TODO: This decision about using KV mode or not,
+// should be taken at a top level rather than pushing it down to individual functions via an enum.
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Default,
+    Eq,
+    PartialEq,
+    serde::Deserialize,
+    serde::Serialize,
+    strum::Display,
+    strum::EnumString,
+)]
+#[router_derive::diesel_enum(storage_type = "pg_enum")]
+#[serde(rename_all = "snake_case")]
+#[strum(serialize_all = "snake_case")]
+pub enum MerchantStorageScheme {
+    #[default]
+    PostgresOnly,
+    RedisKv,
+}
+
 #[derive(
     Clone,
     Copy,