This change removes temporary diagnostic code that was added to investigate a specific system error. It keeps the codebase cleaner now that the investigation is complete, with no expected impact on day-to-day users.

This reverts commit 43649c3c9954551134eace09e84584aafaa1c5c6. It was added on a temporary basis to investigate the error https://runbot.odoo.com/odoo/error/234669, it has achieved its goals and can now be removed.

This update removes outdated RPC services that were phased out in Odoo 19.0. This change improves system stability and prepares for future updates, aligning with the transition to newer, more efficient communication methods. The removal supports ongoing efforts to simplify Odoo's architecture.

The RPC services are all deprecated in 19.0. This work unexpose the `db` service from XMLRPC, it is still accessible from the /web/database/manager page. It also prepares the actual removal of xmlrpc by moving all the utilities we wanna keep outside of the `odoo.services` module.

Documentation: https://www.odoo.com/documentation/19.0/developer/reference/external_api.html#migrating-from-xml-rpc-json-rpc
Presentation at OXP-2025: https://youtu.be/Fe6Noh_G8KA

This update removes the 'activity_name' field from VoIP call records. This simplifies the data structure and reduces potential confusion for users. The change improves data consistency and streamlines reporting related to VoIP calls.

Remove activity_name field on voip.call

Task-5349683

This update removes outdated boolean fields (`request_unit_half` and `request_unit_hours`) from the holiday request system. These fields were previously used but have been superseded by a more efficient method, streamlining the system and reducing potential complexity. This change improves data consistency and simplifies future updates.

The boolean fields `request_unit_half` and `request_unit_hours` are now unused, as their functionality is fully covered by `leave_type_request_unit`. They are therefore removed.

task-5262190