Both `bdk_electrum` and `bdk_esplora` now report the exact block
that the transaction is in, which removes the need for having the
old `ConfirmationTimeHeightAnchor` and `ConfirmationHeightAnchor`.
This PR introduces a new, simpler anchor type that can be modified
to support additional data in the future.
The previous `TxOut` for transactions received from an external
wallet may be optionally added as floating `TxOut`s to `TxGraph`
to allow for fee calculation.
This PR removes `RelevantTxids` from the electrum crate and tracks
transactions in a `TxGraph`. This removes the need to separately
construct a `TxGraph` after a `full_scan` or `sync`.
Fixed a logic error in `construct_update_tip` in `electrum_ext.rs` that caused
the local chain tip to always be a block behind the newest confirmed block.
Coinbase transactions cannot exist in the mempool and be unconfirmed.
`TxGraph::try_get_chain_position` should always return `None` for coinbase
transactions not anchored in best chain.