The POS fiscal integration now sends buyer address details only when they are actually available. This avoids transmitting placeholder values like “N/A”, which makes the submitted data cleaner and more accurate for Fiskaly.

In this commit:
-------------------
- Buyer address fields are optional and should only be sent to Fiskaly when
  they are actually available.
- Avoid sending placeholder values like "N/A". If the data is not present, the
  fields should simply be omitted from the request.

task: 6113133

This update brings back automated flow tests for the French Point of Sale payment reporting and invoicing process. It helps ensure the merged e-reporting and e-invoicing logic continues to work as expected and reduces the risk of regressions.

During the merge of l10n_fr_pdp e-reporting and e-invoicing, some tests had to be removed.

Task-6296356