[IMP] website*: Improve the settings form view

addons/website/models/res_config.py

addons/website/models/website.py

addons/website/views/res_config_views.xml

...s/website_crm/views/website_crm_config_settings_views.xml

addons/website_livechat/models/website.py

addons/website_livechat/views/res_config.xml

addons/website_sale/models/res_config.py

addons/website_sale/views/res_config_view.xml

addons/website_sale_delivery/__manifest__.py

...ite_sale_delivery/views/website_config_settings_views.xml

addons/website_slides/view/res_config.xml

addons/website_twitter/models/website_twitter_config.py

.../website_twitter/views/website_twitter_settings_views.xml