[FIX] sale/website_quote: inherit the sale order report to show the validity date
[REF] website_quote: displayed string of validity_date field changed from 'Validity Date' to 'Expiry Date'
Merge pull request #1563 from odoo-dev/saas-4-sale-report-validity-date-sle

website_quote: renamed validity date to expiry date & adapted the sale order report to display the expiry date in website_quote module instead of sale module