refactor: Use typesafe Wtxid in compact block encoding message, instead of ambiguous uint256.

Wtxid/Txid types introduced in #28107

src/net_processing.cpp

@@ -1006,7 +1006,7 @@ private:
     /** Orphan/conflicted/etc transactions that are kept for compact block reconstruction.
      *  The last -blockreconstructionextratxn/DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN of
      *  these are kept in a ring buffer */
-    std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(g_msgproc_mutex);
+    std::vector<std::pair<Wtxid, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(g_msgproc_mutex);
     /** Offset into vExtraTxnForCompact to insert the next tx */
     size_t vExtraTxnForCompactIt GUARDED_BY(g_msgproc_mutex) = 0;