Merge #2028: Add last_evicted field to TxNode

3fb768b feat(chain)!: Add `last_evicted` field to `TxNode` (志宇)

Pull request description:

  ### Description

  All `last_evicted` field to `TxNode` and remove `TxGraph::get_last_evicted` method.

  ### Notes to the reviewers

  `get_last_evicted` was added as adding fields to `TxNode` is a breaking change. However, we are going to break `bdk_chain` in the next release so a breaking change now is okay.

  ### Changelog notice

  ```md
  Added:
  - `last_evicted` field is added to `TxNode`.

  Removed:
  - `TxGraph::get_last_evicted` method is removed.
  ```

  ### Checklists

  #### All Submissions:

  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)

  #### New Features:

  ~* [ ] I've added tests for the new feature~
  * [x] I've added docs for the new feature

ACKs for top commit:
  oleonardolima:
    ACK 3fb768b
  LagginTimes:
    ACK 3fb768b

Tree-SHA512: 7dc5f68d8a49f10dc16e5ff5b00a02ee991eea832cd7ac96d454b5fb44067c868338921f428d8fdaad38e491c4f8f25baa119dc6de85b1e6c22cab36d95cb423

Author: evanlinjin

crates/chain/src/tx_graph.rs

@@ -220,6 +220,8 @@ pub struct TxNode<'a, T, A> {
     pub first_seen: Option<u64>,
     /// The last-seen unix timestamp of the transaction as unconfirmed.
     pub last_seen: Option<u64>,
+    /// The last-evicted-from-mempool unix timestamp of the transaction.
+    pub last_evicted: Option<u64>,
 }
 
 impl<T, A> Deref for TxNode<'_, T, A> {
@@ -342,6 +344,7 @@ impl<A> TxGraph<A> {
                 anchors: self.anchors.get(&txid).unwrap_or(&self.empty_anchors),
                 first_seen: self.first_seen.get(&txid).copied(),
                 last_seen: self.last_seen.get(&txid).copied(),
+                last_evicted: self.last_evicted.get(&txid).copied(),
             }),
             TxNodeInternal::Partial(_) => None,
         })
@@ -378,6 +381,7 @@ impl<A> TxGraph<A> {
                 anchors: self.anchors.get(&txid).unwrap_or(&self.empty_anchors),
                 first_seen: self.first_seen.get(&txid).copied(),
                 last_seen: self.last_seen.get(&txid).copied(),
+                last_evicted: self.last_evicted.get(&txid).copied(),
             }),
             _ => None,
         }
@@ -410,13 +414,6 @@ impl<A> TxGraph<A> {
         })
     }
 
-    /// Get the `last_evicted` timestamp of the given `txid`.
-    ///
-    /// Ideally, this would be included in [`TxNode`], but that would be a breaking change.
-    pub fn get_last_evicted(&self, txid: Txid) -> Option<u64> {
-        self.last_evicted.get(&txid).copied()
-    }
-
     /// Calculates the fee of a given transaction. Returns [`Amount::ZERO`] if `tx` is a coinbase
     /// transaction. Returns `OK(_)` if we have all the [`TxOut`]s being spent by `tx` in the
     /// graph (either as the full transactions or individual txouts).