test: rename CBlockHeader .hash -> .hash_hex for consistency

Note that we unfortunately can't use a scripted diff here, as the
`.hash` symbol is also used for other instances (e.g. CInv).

test/functional/feature_dersig.py

@@ -92,7 +92,7 @@ class BIP66Test(BitcoinTestFramework):
         peer.send_and_ping(msg_block(block))
         assert_equal(self.nodes[0].getblockcount(), DERSIG_HEIGHT - 1)
         self.test_dersig_info(is_active=True)  # Not active as of current tip, but next block must obey rules
-        assert_equal(self.nodes[0].getbestblockhash(), block.hash)
+        assert_equal(self.nodes[0].getbestblockhash(), block.hash_hex)
 
         self.log.info("Test that blocks must now be at least version 3")
         tip = block.hash_int
@@ -100,7 +100,7 @@ class BIP66Test(BitcoinTestFramework):
         block = create_block(tip, create_coinbase(DERSIG_HEIGHT), block_time, version=2)
         block.solve()
 
-        with self.nodes[0].assert_debug_log(expected_msgs=[f'{block.hash}, bad-version(0x00000002)']):
+        with self.nodes[0].assert_debug_log(expected_msgs=[f'{block.hash_hex}, bad-version(0x00000002)']):
             peer.send_and_ping(msg_block(block))
             assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
             peer.sync_with_ping()