[ADD] estate_auction: add auction functionality to real estate module

[ardo-odoo]

• Implement automated auction sale mode for properties
• Create countdown timer for active auctions
• Add automatic auction closing via scheduled cron job
• Implement auction-specific offers handling
• Send email notifications upon offer acceptance/rejection
• Add web interface for placing bids on auction properties
• Update property views with auction-specific UI components

[robodoo]