store opt in ip address and url when users take action and subscribe

[Finish #73815250]

Conflicts:
	app/controllers/api/members_controller.rb
	app/models/user.rb
	app/models/user_activity_event.rb
	db/schema.rb
	spec/controllers/api/action_pages_controller_spec.rb
make constants private

Conflicts:
	app/controllers/api/members_controller.rb
opt in fields support for #create_from_salsa