## Description
The pivot view of the budget analysis can be really slow for large database with lots of `crossovered.budget.lines`. This issue is also present if one exports the view to the Dashboard app.

## Analysis
The pivot view will request multiple `read_group`, computing the sum of `practical_amount`, triggering it's compute. Said compute loops over all lines, making a separate SQL query for each. In the context of having a large amount lines, the inherent cost of running a query (serialization/deserialization, network transfer) can accumulate to some non-negligible amount.

## Fix
Group by the lines on their date-range and account_id. In the case of line that has an `account.analytic.line` associated with it, we also make sure that if a `general_budget_id` is present on the `crossovered.budget.lines`, then the accounts of the budget should match those of the analytic line.

## Benchmark
Database on 16.0, 17k `crossovered.budget.lines`, 18k `account.analytic.line`, 31k `account.move.line`.
Loading the Budget Analysis pivot view (lines have an analytic account on them)

|             | Before   | After    |
|-------------|----------|----------|
| Timing      | 40 secs  | 3.1 secs |
| Query count | 39k      | 150      |

Loading the Budget Analysis pivot view (lines have *no* analytic account on them)

|             | Before  | After  |
|-------------|---------|--------|
| Timing      | 70 secs | 4 secs |
| Query count | 35k     | 130    |

## Reference
opw-3535910
opw-3573566

Forward-Port-Of: odoo/enterprise#51282
Forward-Port-Of: odoo/enterprise#49871