List supported banks (Partner API)

Returns the list of business activity categories and their activities. This endpoint is equivalent to `/static/activities` but filters out disabled categories and activities. **Use this endpoint to:** - Get valid activity categories and activities for business registration - Display activity options in your application - Validate activity information before creating businesses **Activity Information:** - Only enabled categories and activities are returned - Activities are grouped by category - Supports language selection via `Accept-Language` header (defaults to French) - Categories and activities are sorted alphabetically **Language Support:** - Send `Accept-Language: en` for English - Send `Accept-Language: fr` for French (default) **Authentication:** Requires API key headers. The authenticated business must be a service provider.