partial commit to fix wallet utils

this commit provide a lot of changes in will-settings including export to ics calendar file.

heirs.py

@@ -34,6 +34,7 @@ from electrum.transaction import (
     # TxOutput,
 )
 from electrum.util import (
+    BitcoinException,
     bfh,
     read_json_file,
     to_string,
@@ -43,7 +44,7 @@ from electrum.util import (
 
 from .util import Util
 from .willexecutors import Willexecutors
-from electrum.util import BitcoinException
+
 if TYPE_CHECKING:
     from .simple_config import SimpleConfig
 
@@ -73,10 +74,10 @@ def reduce_outputs(in_amount, out_amount, fee, outputs):
 def create_op_return_script(data_hex: str) -> bytes:
     """Crea scriptpubkey OP_RETURN in bytes"""
     data = bytes.fromhex(data_hex)
-    
+
     if len(data) > 80:
         raise ValueError("OP_RETURN data too big (max 80 bytes)")
-    
+
     # Costruzione manuale: OP_RETURN + push data
     if len(data) <= 75:
         # Formato più comune: OP_RETURN + 1-byte length + data
@@ -84,7 +85,7 @@ def create_op_return_script(data_hex: str) -> bytes:
     else:
         # Per dati più grandi (fino a 80) si usa OP_PUSHDATA1
         script = b'\x6a\x4c' + bytes([len(data)]) + data
-    
+
     return script
 
 def prepare_transactions(locktimes, available_utxos, fees, wallet):
@@ -162,7 +163,7 @@ def prepare_transactions(locktimes, available_utxos, fees, wallet):
             random.shuffle(outputs)
 
         #op_return_text = "Hello Bal!"
-    
+
         ## Convert text to hex
         #op_return_hex = op_return_text.encode('utf-8').hex()
         #op_return_script = create_op_return_script(op_return_hex)