Error when creating accounts in top level group

[lasuk]

Problem

The mirror_accounts method fails for accounts assigned to a top-level group/category such as '/Assets'.

import pandas as pd
from cashctrl_ledger import CashCtrlLedger

account = pd.DataFrame({
    'account': ['1021', '1022', '1023'],
    'currency': ['CHF', 'EUR', 'USD'],
    'text': ['Credit Suisse - CHF', 'Credit Suisse - EUR', 'Credit Suisse - USD'],
    'group': ['/Assets/Anlagevermögen', '/Assets', '/Assets'],
})

cc_ledger = CashCtrlLedger()

# This works
cc_ledger.mirror_account_chart(account.iloc[[0]].copy(), delete=False)

# This fails
cc_ledger.mirror_account_chart(account.iloc[[1]].copy(), delete=False)
# Traceback (most recent call last):
#   File "<stdin>", line 1, in <module>
#   File "/Users/lukas/macx/cashctrl_ledger/cashctrl_ledger/ledger.py", line 164, in mirror_account_chart
#     self.update_account(
#   File "/Users/lukas/macx/cashctrl_ledger/cashctrl_ledger/ledger.py", line 210, in update_account
#     "categoryId": self._client.account_category_to_id(group),
#                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#   File "/Users/lukas/macx/cashctrl_api/cashctrl_api/cashed_client.py", line 297, in account_category_to_id
#     raise ValueError(f"No id found for account category path: {path}")
# ValueError: No id found for account category path: /Assets

Tasks

1. Extend the test for mirror_accounts to include accounts at a top level category. Show that this test fails with the current implementation.
2. Change the implementation to make the test pass.