nBTC Redeem: handle reorgs

[sczembor]

1. Identify Stuck Redeems: Find any redemption in Reorg status that hasn't moved for some time (maybe 1 hour)
2. Reset to Pending: Update those redeems back to Pending and set their used UTXOs back to Available so they can be re-tried

[robert-zaremba]

TODO: we also need to redo tx attempt.
Today, we stop tracking Bitcoin redeem transaction once indexer will mark it as finalized. But technically we can have super unlikely deep reorg. In such case we should try to broadcast again the tx.