Add disconnect-block functionality for `LocalChain` and `Wallet`

[evanlinjin]

Describe the enhancement

impl LocalChain {
    /// Removes blocks from the given `block_id`.
    ///
    /// Will remove blocks with a height equal or greater than `block_id`,
    /// but only if `block_id` exists in the chain.
    pub fn disconnect_block(&mut self, block_id: BlockId) -> ChangeSet {
        todo!()
    }
}

Use case

The APIs of utreexod (based on btcd) and bitcoind ZeroMQ has disconnect-block notifications. BDK should be able to handle such notifications.

[LLFourn]

post fix concept NACK. I interpret these messages are informational (something to log out). You just need to wait for the block that replaces it which will automatically evict the block. Eagerly evicting blocks means you end up in a state where your wallet says it has less money than it actually does. This could be unexpected and harmful -- imagine you have a emergency notification that goes out to the whole company if there is a sudden drop in Bitcoin holdings. If you just wait for the new block any funds you received in the evicted block are likely to appear in the new one so you never end up in this state.

Is there some motivation for reacting to these messages that I'm missing?

[notmandatory]

looks like this was fixed with bitcoindevkit/bdk#1276.