[19.0][MIG] hr_expense_employee_analytic_default: Migration to 19.0

[dnplkndll]

Port of hr_expense_employee_analytic_default to 19.0.

Non-mechanical adaptations worth flagging

• Odoo 19 Support: Adapted the _get_distribution override inside models/account_analytic_distribution_model.py to check both address_id and work_contact_id for resolving default employee analytic cost-centers.
• Unit Tests: Completely rewrote the test suite to use standard Odoo 19 transaction patterns, ensuring direct and robust employee-analytic mapping test cases.

[dnplkndll]

Replaced by #350 — source branch moved from dnplkndll fork to ledoent organization fork. Same commits (HEAD 34d7768), no content change.