Add proper CI to facilitate checking PR

[EtienneDx]

In order to facilitate the checking of new features, a CI can be put into place.

For our purpose, the new CI should, on push:

• Build the artefacts
• Upload the frontend to a bucket
  • One per CR would work, as the bucket would be deleted after the CR is merged/closed
• Creates a disabled CloudFront distribution to grant access to said bucket (single region)
• Upload the backend artefacts to a separate bucket
  • One for all CRs would be better here, to simplify access
• Create a cloudwatch log group
• Create IAM user to access said group + Upload This Action should be reusable

A separate manual action should start the server when manually triggered:

• Validate the frontend stack existence / status
• Enable the cloudfront distribution
• Create VPC etc
• Start an ec2 instance with a custom build script which:
  • Downloads the backend artefacts from the artefact bucket
  • Start a database
  • Start the different services
  • Send logs to the log group
  • Run custom startup script to seed the environment (sql/ts script?) @Lerri-Cofannos any input on this?
• Upload config.json to frontend S3 bucket, giving the frontend the URL to the back
• Create an alarm if the server stays up for more than a given time
  • Potentially destroying the stack?

Another manual action should stop the server when manually triggered:

• Remove the backend stack entirely

A final stack should be used on merge, on close:

• Remove the backend stack if it is running
• Remove the frontend stack
• Any failure should trigger an alarm

[Lerri-Cofannos]

The backend should be the one to seed the database, using the regular functions used for creating entities. I suggest adding a script that gets triggered at launch if a certain environnement variable is set. The variable could be injected in commands through a flag, or directly set in the CI.

[EtienneDx]

Here's a simplified graph of the goal for this CR.This will need to be further refined during the implementation

[EtienneDx]

Closed with #45