Support shortlinks for Twilio inboxes

Twilio now supports [short links that provide better insights about click rates]( and interactions with messages (WhatsApp and SMS), after setup them up on Twilio dashboards, it is required to add an additional parameter shorten_urls=true when creating a message.

In order to do that, apparently lines 45 to 48 in /app/models/channel/twilio_sms.rb should accept that parameter, however, enabling it probably will require a checkbox or other UX for the user to opt-in.

Such messages can potentially be a game changer for some users and we can be able to trigger events and analyze our funnel after the message is delivered.