Allow using a custom sender ID instead of the Twilio phone number

Problem/Motivation

Twilio allows to use custom alphanumeric Sender ID instead of the Twilio phone number (not available in all countries tough). At this time, the module use only the Twilio phone number to send messages. It can be override thanks to #2574747 → but the implementation is not complete.

Proposed resolution

Add a new parameter called : "From". By default, it will take the Twilio phone number.

Remaining tasks

Write patch

User interface changes

Rules UI, Action UI and Admin test page, a new field has been added : From, and can replaced by a token. The default value is the Twilio phone number.

API changes

None. If a custom sender id is not provided, the twilio phone number will be taken instead.