Merge #13669: Tests: Cleanup create_transaction implementations

44bbceeef1 [Tests] Cleanup feature_block.py, remove unnecessary PreviousSpendableOutput object (Conor Scott)
736f941424 [Tests] Cleanup extra instances of create_transaction (Conor Scott)
157651855f [Tests] Rename create_tx and move to blocktools.py (Conor Scott)

Pull request description:

  There currently exist seven ([1](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_cltv.py#L52-L60), [2](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_csv_activation.py#L88-L95) [3](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_dersig.py#L40-L48), [4](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_nulldummy.py#L100-L108), [5](https://github.com/bitcoin/bitcoin/blob/master/test/functional/test_framework/util.py#L529-L535), [6](https://github.com/bitcoin/bitcoin/blob/master/test/functional/test_framework/blocktools.py#L120-L129), [7](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_block.py#L1218-L1220)) implementations of a function called something similar to `create_transaction` in the functional tests, some of which are exact copies of each other.

  This PR aims to clean this up into [three different cases implemented in blocktools.py](https://github.com/conscott/bitcoin/blob/create_tx_cleanup/test/functional/test_framework/blocktools.py#L121-L149)
  1. `create_tx_with_script`: Return transaction object spending generic tx output optionally specifying scriptSig and scriptPubKey
  2. `create_transaction`: Return transaction object spending coinbase tx
  2. `create_raw_transaction`: Return raw transaction (hex string) spending coinbase tx

  I am not committed to any of these function names, so I'll gladly take suggestions on there.

  Additionally there are some related cleanups to feature_block.py tests, specifically removing the [PreviousSpendableOutput](https://github.com/conscott/bitcoin/blob/master/test/functional/feature_block.py#L51-L54) object, which seems like an unnecessary layer given that every instance spends the 0 output.

Tree-SHA512: 63c6233b6f0942c81ba1ca67ea6770809b8c9409314c6d4cf8e5a3991cb9ee92b22bebe88c0dde45cd71e754eb351230c4c404b70ff118f5f43c034452ada65c

test/functional/feature_csv_activation.py

@@ -47,7 +47,7 @@ from itertools import product
 from io import BytesIO
 import time
 
-from test_framework.blocktools import create_coinbase, create_block
+from test_framework.blocktools import create_coinbase, create_block, create_transaction
 from test_framework.messages import ToHex, CTransaction
 from test_framework.mininode import P2PDataStore
 from test_framework.script import (
@@ -85,15 +85,6 @@ def relative_locktime(sdf, srhb, stf, srlb):
 def all_rlt_txs(txs):
     return [tx['tx'] for tx in txs]
 
-def create_transaction(node, txid, to_address, amount):
-    inputs = [{"txid": txid, "vout": 0}]
-    outputs = {to_address: amount}
-    rawtx = node.createrawtransaction(inputs, outputs)
-    tx = CTransaction()
-    f = BytesIO(hex_str_to_bytes(rawtx))
-    tx.deserialize(f)
-    return tx
-
 def sign_transaction(node, unsignedtx):
     rawtx = ToHex(unsignedtx)
     signresult = node.signrawtransactionwithwallet(rawtx)