Update Telnyx to be compatible with Version 2 (v2)

Endpoint: https://sms.telnyx.com/messages
Header: X-Profile-Secret
Message field: body

I inspected armembersms_2.1.zip. Its Telnyx integration is outdated and hard-coded to use:

The current Telnyx Messaging API from Telnyx.com uses:

Endpoint: https://api.telnyx.com/v2/messages
Header: Authorization: Bearer YOUR_API_KEY
Message field: text

Please update this