[Analytics] - Refund status serialization issue for ckh analytics

[ivor11]

pub enum RefundStatus {
    Failure,
    ManualReview,
    #[default]
    Pending,
    Success,
    TransactionFailure,
}

RefundStatus enum is serialized to snake_case but when the same event is pushed to kafka it is retained in camelCase.
Due to this refund_status in clickhouse refunds table is in camelCase and ckh queries for analytics return 0 when refund_status = 'success' filter is applied

[ivor11]

possible solns

• find a way to use camelCase refund_status values for ckh queries
• use #[serde(rename_all = "snake_case")] on RefundStatus and run migrations on clickhouse to match psql enum values