Returns a list of the sites a brand has.
When retrieving sites for a brand, the API returns the following information for each site:

• location_id: Unique identifier for the site
• name: Display name of the site
• status: Current operational status (OPEN, CLOSED, READY_TO_OPEN)
• api_access: Object containing API access permissions for different services
• phone_number: Contact phone number for the site
• type: Site type (RESTAURANT, ON_DEMAND_CONVENIENCE, UNKNOWN)
• on_vacation: Boolean indicating if the site is currently on vacation
• timezone: Timezone of the site (e.g., "Europe/London")
• tabletless: Boolean indicating whether the site operates without a tablet (ROM).