[test] rename SegwitVersion1SignatureHash()

The function implementing segwit v0 signature hash was originally named
SegwitVersion1SignatureHash() (presumably before segwit v0 was named
segwit v0). Rename it to SegwitV0SignatureHash().

Also rename SignatureHash() to LegacySignatureHash() for disambiguation.

test/functional/feature_block.py

@@ -46,7 +46,7 @@ from test_framework.script import (
     OP_RETURN,
     OP_TRUE,
     SIGHASH_ALL,
-    SignatureHash,
+    LegacySignatureHash,
     hash160,
 )
 from test_framework.test_framework import BitcoinTestFramework
@@ -532,7 +532,7 @@ class FullBlockTest(BitcoinTestFramework):
             # second input is corresponding P2SH output from b39
             tx.vin.append(CTxIn(COutPoint(b39.vtx[i].sha256, 0), b''))
             # Note: must pass the redeem_script (not p2sh_script) to the signature hash function
-            (sighash, err) = SignatureHash(redeem_script, tx, 1, SIGHASH_ALL)
+            (sighash, err) = LegacySignatureHash(redeem_script, tx, 1, SIGHASH_ALL)
             sig = self.coinbase_key.sign_ecdsa(sighash) + bytes(bytearray([SIGHASH_ALL]))
             scriptSig = CScript([sig, redeem_script])
 
@@ -1312,7 +1312,7 @@ class FullBlockTest(BitcoinTestFramework):
         if (scriptPubKey[0] == OP_TRUE):  # an anyone-can-spend
             tx.vin[0].scriptSig = CScript()
             return
-        (sighash, err) = SignatureHash(spend_tx.vout[0].scriptPubKey, tx, 0, SIGHASH_ALL)
+        (sighash, err) = LegacySignatureHash(spend_tx.vout[0].scriptPubKey, tx, 0, SIGHASH_ALL)
         tx.vin[0].scriptSig = CScript([self.coinbase_key.sign_ecdsa(sighash) + bytes(bytearray([SIGHASH_ALL]))])
 
     def create_and_sign_transaction(self, spend_tx, value, script=CScript([OP_TRUE])):