scripted-diff: replace remaining Python test equality asserts

Some Python functional tests still use plain `assert x == y`.
The earlier commits convert the ambiguous assert patterns by hand, so this commit can rewrite the remaining safe cases mechanically.
The verify script excludes `wallet_bumpfee.py`, `test_framework/netutil.py`, and `test_framework/authproxy.py`, which still contain assert forms that the plain line-based substitution would misidentify.

-BEGIN VERIFY SCRIPT-
perl -pi -e 's/^(\s*)assert (.+?) == ([^,#]+?)$/\1assert_equal(\2, \3)/' $(git ls-files -- 'test/functional' \
':(exclude)test/functional/wallet_bumpfee.py' ':(exclude)test/functional/test_framework/netutil.py' ':(exclude)test/functional/test_framework/authproxy.py')
-END VERIFY SCRIPT-

test/functional/data/invalid_txs.py

@@ -123,8 +123,8 @@ class SizeTooSmall(BadTxTemplate):
         tx = CTransaction()
         tx.vin.append(self.valid_txin)
         tx.vout.append(CTxOut(0, CScript([OP_RETURN] + ([OP_0] * (MIN_PADDING - 2)))))
-        assert len(tx.serialize_without_witness()) == 64
-        assert MIN_STANDARD_TX_NONWITNESS_SIZE - 1 == 64
+        assert_equal(len(tx.serialize_without_witness()), 64)
+        assert_equal(MIN_STANDARD_TX_NONWITNESS_SIZE - 1, 64)
         return tx
 
 # reject a transaction that contains a witness