This commit changes the `LocalChain` implementation to have blocks
stored as a linked-list. This allows the data-src thread to hold a
shared ref to a single checkpoint and have access to the whole history
of checkpoints without cloning or keeping a lock on `LocalChain`.
The APIs of `bdk::Wallet`, `esplora` and `electrum` are also updated to
reflect these changes. Note that the `esplora` crate is rewritten to
anchor txs in the confirmation block (using the esplora API's tx status
block_hash). This guarantees 100% consistency between anchor blocks and
their transactions (instead of anchoring txs to the latest tip).
`ExploraExt` now has separate methods for updating the `TxGraph` and
`LocalChain`.
A new method `TxGraph::missing_blocks` is introduced for finding
"floating anchors" of a `TxGraph` update (given a chain).
Additional changes:
* `test_local_chain.rs` is refactored to make test cases easier to
write. Additional tests are also added.
* Examples are updated.
* Fix `tempfile` dev dependency of `bdk_file_store` to work with MSRV
Co-authored-by: LLFourn <lloyd.fourn@gmail.com>
Other changes:
* The `async-https` feature of `bdk_esplora` is no longer default.
* Rename `ObservedAs` to `ChainPosition`.
* Set temporary MSRV to 1.60.0 to compile all workspace members will all
features.
* `ElectrumUpdate::missing_full_txs` now returns a `Vec<Txid>` so we
don't keep a reference to the passed-in `graph`.
* `ElectrumUpdate::finalize*` methods now takes in `missing` txids
instead of `full_txs`. `Client::batch_transaction_get` is called
within the methods.
Other changes:
* `wallet::ChangeSet` is now made public externally. This is required as
a wallet db should implement `PersistBackend<wallet::ChangeSet>`.
This corresponds to `keychain::KeychainChangeSet` but for the redesigned
structures with `LocalChain`.
This structure is now used in `Wallet` as well as the examples.
