The HR contract module now provides a wage normalization method needed by ESG reporting integrations. This places the calculation where dependent ESG features can access it without requiring the payroll module, improving compatibility with lighter HR setups.

Before this commit, the method `_get_normalized_wage` should have been declared in `hr_contract` rather than `hr_payroll` since the esg bridge depends only on hr_contract.

This commit adds the method in `hr_contract` with a more approximate approach given the available information.

Calendar events now store video call references in a way that can be searched more efficiently. This should improve performance for calendar operations that need to find events linked to a video call, with no expected change to user workflows.

https://github.com/odoo/odoo/pull/199532 introduce a `One2many` on `videocall_channel_id`.
This PR index `videocall_channel_id`.