Add non-segwit Firo support.

Rework tests to combine atomic and xmr test cases.
Modify btc interface to support P2WSH_nested_in_BIP16_P2SH
Add coin feature tests to test_btc_xmr.py

basicswap/basicswap_util.py

@@ -9,8 +9,8 @@ import struct
 import hashlib
 from enum import IntEnum, auto
 from .util.address import (
-    decodeAddress,
     encodeAddress,
+    decodeAddress,
 )
 from .chainparams import (
     chainparams,