Merge bitcoin/bitcoin#22998: test: use MiniWallet for make_utxo helper in feature_rbf.py

f680d27155 test: use MiniWallet for make_utxo helper in feature_rbf.py (Sebastian Falbesoner)
0f27524602 test: scale amounts in test_doublespend_tree down by factor 10 (Sebastian Falbesoner)
d1e2481274 test: scale amounts in test_doublespend_chain down by factor 10 (Sebastian Falbesoner)

Pull request description:

  This PR aims to further increase MiniWallet usage in the functional test feature_rbf.py by using it in the `make_utxo(...)` helper, which is the only part that needs a wallet for most sub-tests. In order to do that, the amounts for the utxos have to be scaled down in two sub-tests first (`test_doublespend_chain` and `test_doublespend_tree`, see first two commits), since we need amounts passed to `make_utxo` than can be funded by only one input. For creating UTXOs with a value of 50 BTC, we'd need to implement a method for consolidating multiple utxos into one first, which seems to be overkill.

  Note that after this PR's change, there is only one sub-test left (`test_rpc`) that needs the wallet compiled into bitcoind.

ACKs for top commit:
  MarcoFalke:
    review ACK f680d27155 🦐

Tree-SHA512: 46c8c245086a9e79855c4ede2f8f412333cf2658136805196b203b3567c89398d77fcb80715c0bb72fdc84331cc67544b2fdc259193a3adcb2fc36e147c26fce

test/functional/test_framework/wallet.py

@@ -180,8 +180,10 @@ class MiniWallet:
         return {'txid': tx_info['txid'], 'wtxid': tx_info['wtxid'], 'hex': tx_hex, 'tx': tx}
 
     def sendrawtransaction(self, *, from_node, tx_hex):
-        from_node.sendrawtransaction(tx_hex)
+        txid = from_node.sendrawtransaction(tx_hex)
         self.scan_tx(from_node.decoderawtransaction(tx_hex))
+        return txid
+
 
 def make_chain(node, address, privkeys, parent_txid, parent_value, n=0, parent_locking_script=None, fee=DEFAULT_FEE):
     """Build a transaction that spends parent_txid.vout[n] and produces one output with