Multi: Update implementation of dex dcr Wallet interface

[ukane-philemon]

This PR updates the "replace" dex package to use changes in decred/dcrdex#2855 cuz it is more up to date and fixes a concurrent map write bug that came up during testing a6c7153.

2024-07-09 14:45:37.928 [INF] LTC: Current sync progress update is on block 2498000, target sync block is 3344058
2024-07-09 14:45:38.788 [INF] BTC: Current sync progress update is on block 2837000, target sync block is 2867061
2024-07-09 14:45:40.026 [INF] LTC: Processed 578 blocks in the last 10.03s (height 2500314, 2022-09-05 01:49:48 +0100 WAT)
fatal error: concurrent map writes

goroutine 20256 [running]:
github.com/crypto-power/cryptopower/ui/page/components.(*WalletSyncInfo).ListenForNotifications.func1({{0xc00b6a4d96?, 0x0?}, 0x7000102?, 0x0?, 0x0?})
        /Users/philemon/Desktop/osp/cryptopower/ui/page/components/wallet_sync_info.go:551 +0xd2
github.com/crypto-power/cryptopower/ui/page/components.(*WalletSyncInfo).ListenForNotifications.func3(0xc0018eae78)
        /Users/philemon/Desktop/osp/cryptopower/ui/page/components/wallet_sync_info.go:573 +0x55
github.com/crypto-power/cryptopower/libwallet/assets/dcr.(*Asset).publishAddressDiscoveryProgress(0xc000172240)
        /Users/philemon/Desktop/osp/cryptopower/libwallet/assets/dcr/syncnotification.go:396 +0x5b
github.com/crypto-power/cryptopower/libwallet/assets/dcr.(*Asset).updateAddressDiscoveryProgress(0xc000172240, 0x4062c00000000000)
        /Users/philemon/Desktop/osp/cryptopower/libwallet/assets/dcr/syncnotification.go:377 +0x579
created by github.com/crypto-power/cryptopower/libwallet/assets/dcr.(*Asset).discoverAddressesStarted in goroutine 772
        /Users/philemon/Desktop/osp/cryptopower/libwallet/assets/dcr/syncnotification.go:303 +0x1ca