Fixes:
- Fast-sync potential problem fix
- Inconsistent balance on mobile wallets after UTXO rescan in node
- Fixed node slow-down if many shielded txs are broadcasted
- Attempting to restore txs after rollback
- Fixed possible API crash on wallet with Lelantus transactions
Improvements:
- Added automatic rollback limit of 60 blocks
- Multi-threaded Lelantus withdrawal proof generation
- Faster UTXO rescan in wallet