feat: add unique constraint restriction for KV (#3723)

Co-authored-by: hyperswitch-bot[bot] <148525504+hyperswitch-bot[bot]@users.noreply.github.com>

crates/redis_interface/src/errors.rs

@@ -50,6 +50,8 @@ pub enum RedisError {
     SetHashFailed,
     #[error("Failed to set hash field in Redis")]
     SetHashFieldFailed,
+    #[error("Failed to add members to set in Redis")]
+    SetAddMembersFailed,
     #[error("Failed to get hash field in Redis")]
     GetHashFieldFailed,
     #[error("The requested value was not found in Redis")]