Documentation for API key-related methods has been clarified so developers better understand required inputs and outputs. This reduces ambiguity during maintenance and integration work without changing user-facing behavior.

Clarify and complete the docstrings of `res.users.apikeys` methods:
- document accepted union types for `scope` and `expiration_date` parameters of method `_generate`, and standardize its `:returns:` and `:rtype:` annotations
- add missing parameter descriptions for `generate` and `revoke`

This update enhances the Balance Sheet report to comply with Generally Accepted Accounting Principles (GAAP). It now ensures that all equity accounts are displayed individually, providing clearer and more accurate financial reporting. This change improves the reliability of financial data for users.

*=l10n_us_reports

In the Balance Sheet, according to the GAAP rules, all equity accounts should be individually visible.

task-6240500