Create a method handling boto3 API

[OtisRed]

Subject of the issue:

We should introduce implementation on Boto3 API.

Technical description

We should distinguish between: send_to_ses (for actual sending emails) and send_to_etheral (for testing purposes) based on send_email distinction method provided in #426.

• current send_message method in backend/resources/contact.py should be renamed to send_to_etheral and left intact,
• there should be a second send_to_ses method that handles sending messages via Boto3 API to SES.
• define the second method to send text-based emails. It's importnat to define explicitly if it's text or html. We will handle html e-mails later on.

[OtisRed]

Ok so we found another way to solve this