WooCommerce Smart Coupons 8.20.0

* New: Move coupon emails in the WooCommerce email system for better handling
* New: Plain text emails for coupons
* Fix: Coupon actions not working in case of fixed amount gift voucher products
* Fix: Unable to empty coupon expiry time
* Developer: Filter 'wc_sc_calculate_totals_stop_at' to handle discount calculation for store credit
* Update: POT file

* New: Option to add custom style for coupons using CSS
* New: Apply multiple coupons from URL
* New: Setting to allow the buyer to send coupons to someone else (By default: Enabled)
* New: Save original store credit value in the coupon meta when it is auto-generated
* New: Copy coupon code action on coupons dashboard
* New: Get coupon shareable link on coupons dashaboard and edit coupon page
* Update: Support for performing smart coupons actions on order statuses which are added by 3rd party plugins
* Update: Docs, Support & Review links on plugins page
* Update: Admin Footer text for Smart Coupons pages
* Tweak: Export button on coupons dashboard
* Update: POT file

* New: Setting to allow combining of coupons emails when multiple emails are sent to the same recipient
* New: Restrict Coupons by User Roles
* Fix: Store Credit's amount not decreasing even after applying the discount on the renewal order [WooCommerce Subscriptions]
* Update: POT file