[Bounty: 1 XMR] Upgrade bdk library

[binarybaron]

According to a core developer of the bdk library comit-network#1772 can probably be fixed by upgrading to the latest version of the crate. They added a bunch of improvements to the syncing logic.

[binarybaron]

This is currently blocked by bitcoindevkit/bdk#1606. We need a way to migrate the wallet data.

[binarybaron]

Turns out the issue is not really blocking our migration. We can just switch to 1.0.0-alpha version of bdk. The descriptors and keys are derived from our seed. The first sync post-upgrade will take a while but all data currently stored in the sled wallet database can be derived from the blockchain state. We won't loose any data aside from caches.

[binarybaron]

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[binarybaron]

See https://github.com/bitcoindevkit/bdk/pull/1648/files

[binarybaron]

@Einliterflasche You wanna take this on once we merge #109?

[binarybaron]

https://docs.rs/bdk_wallet/latest/bdk_wallet/struct.Wallet.html
https://bookofbdk.com/cookbook/syncing/electrum/