Replace 6 bare assert statements in test/functional/wallet_bumpfee.py with test framework helpers (assert_greater_than, assert_equal).
Bare asserts produce unhelpful AssertionError with no context on failure. The helpers print actual vs expected values.
Changes:
assert bumped_tx["fee"] > -rbftx["fee"]→assert_greater_thanassert bumped_psbt["fee"] > -rbftx["fee"]→assert_greater_thanassert len(oldwtx["walletconflicts"]) > 0→assert_greater_thanassert len(bumpedwtx["details"]) == 1→assert_equalassert bumpedwtx["details"][0]["address"] == new_address→assert_equalassert rbf_node.getbalance() < 49→assert_greater_than(49, ...)
No new imports needed — all helpers already imported. Each replacement preserves the exact same logical condition.
Part of #23119.