**Description**
Opening the Budget Report from any budget record times out on databases
with significant data volume. The request to
`budget.report/formatted_read_grouping_sets` consistently times out,
making the Budget Report completely unusable.

**Root cause:**
`budget.report` is an SQL view that consists of 5 UNION ALL branches.
When the list view loads, the ORM translates the `budget_analytic_id`
domain into a WHERE clause on the outer query wrapping the full UNION
ALL subquery. PostgreSQL cannot push this filter through a UNION ALL as
it's a hard optimization barrier. It must fully materialize the subquery
regardless of which budget is being viewed.

**Fix:**
Override _search on budget.report to extract budget_analytic_id and
budget_line_id conditions from the incoming domain using the Domain API.
budget_line_id is rewritten as Domain('id', op, value) so _to_sql()
correctly emits bl.id in the raw SQL. The resulting domain is injected
in context under budget_line_domain and read in _get_bl_query,
_get_aal_query (base module), and _get_pol_query (purchase module) to
filter budget_line rows inside each branch's LEFT JOIN ON clause.
This also removes the budget_report_budget_line_ids context key from
budget_line._compute_all, unifying both filters under one mechanism.

---

On customer DB (568k `account_analytic_line`, 27k `budget_line`,
116k confirmed `purchase_order_line`, 114k posted vendor bill lines
with purchase link):

| Budget | Before | After |
|---|---|---|
| 8 lines, 730d span | timeout | 2.27s |
| 14 lines | timeout | 2.39s |
| 14 lines, 1095d span | timeout | 1.63s |

- Before: https://explain.dalibo.com/plan/ehed5eb8de251426
- After: https://explain.dalibo.com/plan/db8aef35cag9hg6f

opw-6098047

Forward-Port-Of: odoo/enterprise#119728
Forward-Port-Of: odoo/enterprise#114692