### Issue:
When an analytic plan has applicability lines with a company filter, the applicability is incorrectly applied on views that do not define a `business_domain`, such as Work Centers or Employee views

For example, if a plan has:
- Default Applicability: Unavailable
- A line with Domain: Invoice, Company: My Company, Applicability: Mandatory

Opening the analytic distribution on a Work Center shows `Mandatory` instead of the default `Unavailable`

### Cause:
In commit https://github.com/odoo/odoo/commit/ffcf2ee1a3185ef73db93bfd95625844506692c5 `_get_score` was updated to return `0.5` when the applicability line's company matches the caller's company, even when no `business_domain` is provided

In `_get_applicability`, the loop selects the first rule whose score exceeds the current minimum, which starts at `0`:
https://github.com/odoo/odoo/blob/710e056e5171af2ab72d7d7793da3518f12faf5e/addons/analytic/models/analytic_plan.py#L255-L264

A score of `0.5` is enough to win over the default applicability, so a company-only match on a domain-specific rule incorrectly overrides the default when no `business_domain` is passed

### Steps to reproduce:
- Install `mrp` and `accountant` with demo data
- Enable Analytic Accounting in Settings
- Open the Internal analytic plan and edit its applicability line:
  -- Remove the account prefix
  -- Default Applicability: Unavailable
  -- Domain: Invoice, Company: My Company (SF), Applicability: Mandatory
- Go to Manufacturing > Configuration > Work Centers
- Open any work center and click on Analytic Distribution

Before the fix, Internal is shown as Mandatory instead of Unavailable
Removing the company from the applicability line confirms the issue

opw-6404884

Forward-Port-Of: odoo/odoo#280312