Update the communication message

**What it's the actual situation on ARA ?**
The communication message can be either a text or HTML.

**Describe the solution you'd like**
Saving and fetching HTML is not a good practice. Think of a template that avoid handling HTML code in the communication part.

No files, tests, or entry points are named; start by locating the communication-message code and how it currently saves and fetches text or HTML. Define the template boundary before changing it, with the goal of avoiding HTML handling in the communication part while preserving text and HTML message output.

Written by the indexing model from the issue text.