[ADD] pos_coupon: allow the use of promo and coupon programs in pos

addons/coupon/models/coupon.py

addons/coupon/models/coupon_program.py

addons/coupon/views/coupon_program_views.xml

addons/point_of_sale/models/res_config_settings.py

addons/point_of_sale/static/src/js/Gui.js

addons/point_of_sale/static/src/js/models.js

addons/point_of_sale/tests/test_frontend.py

addons/point_of_sale/views/pos_config_view.xml

addons/point_of_sale/views/res_config_settings_views.xml

addons/pos_coupon/__init__.py

addons/pos_coupon/__manifest__.py

addons/pos_coupon/data/coupon_email_data.xml

addons/pos_coupon/data/default_barcode_patterns.xml

addons/pos_coupon/demo/pos_coupon_demo.xml

addons/pos_coupon/models/__init__.py

addons/pos_coupon/models/barcode_rule.py

addons/pos_coupon/models/coupon.py

addons/pos_coupon/models/coupon_program.py

addons/pos_coupon/models/pos_config.py

addons/pos_coupon/models/pos_order.py