Implement presumed_origin

Before we yield a block for scanning, we save all of the contained script
public keys. Then, when we want the address credited for creating an output,
we read the script public key of the spent output from the database.

Fixes #559.

processor/bitcoin/src/output.rs

@@ -15,6 +15,7 @@ use bitcoin_serai::{
 
 use scale::{Encode, Decode, IoReader};
 use borsh::{BorshSerialize, BorshDeserialize};
+use serai_db::Get;
 
 use serai_client::{
   primitives::{Coin, Amount, Balance, ExternalAddress},
@@ -52,13 +53,35 @@ pub(crate) struct Output {
 }
 
 impl Output {
-  pub fn new(key: <Secp256k1 as Ciphersuite>::G, tx: &Transaction, output: WalletOutput) -> Self {
+  pub fn new(
+    getter: &impl Get,
+    key: <Secp256k1 as Ciphersuite>::G,
+    tx: &Transaction,
+    output: WalletOutput,
+  ) -> Self {
     Self {
       kind: offsets_for_key(key)
         .into_iter()
         .find_map(|(kind, offset)| (offset == output.offset()).then_some(kind))
         .expect("scanned output for unknown offset"),
-      presumed_origin: presumed_origin(tx),
+      presumed_origin: presumed_origin(getter, tx),
+      output,
+      data: extract_serai_data(tx),
+    }
+  }
+
+  pub fn new_with_presumed_origin(
+    key: <Secp256k1 as Ciphersuite>::G,
+    tx: &Transaction,
+    presumed_origin: Option<Address>,
+    output: WalletOutput,
+  ) -> Self {
+    Self {
+      kind: offsets_for_key(key)
+        .into_iter()
+        .find_map(|(kind, offset)| (offset == output.offset()).then_some(kind))
+        .expect("scanned output for unknown offset"),
+      presumed_origin,
       output,
       data: extract_serai_data(tx),
     }