[18.0][ADD] fleet_vehicle_category_analytic: Set analytic account on invoice line from vehicle, via vehicle categories

[arnaudlayec]

This PR is a proposal to be discussed.

Summary

Based on fleet_vehicle_category, it allow to automatically set an Analytic Distribution (analytic_distribution) on invoices lines (account.move.line) when choosing the vehicle on invoices lines.

Usage

Please see USAGE.md. In short: define an analytic account on a vehicle category, and then use the vehicle on an invoice line.

Choice discussion

Dependency with module fleet_vehicle_category

I choose to define the Analytic Account on the fleet.vehicle.category model from the corresponding OCA module.
Indeed, we could think of other way to define this Analytic Account on vehicle:

• directly on vehicle: but very manual and unitary
• on native Odoo object, like fleet.vehicle.model or fleet.vehicle.model.category: but those are really related to vehicle's manufacturer, which is limiting.

Analytic Account instead of Analytic Distribution

I choose to define a single Analytic Account in the vehicle category for simplicity. It could evolve to Analytic Distribution, but the merging logic with invoice lines would need to be defined.
For now, this merging logic is very simple:

• set the analytic account at 100% if not already set (so leave it, for instance, at 50% if it were already modified at 50%)
• leave any other part of the Analytic Distribution in place