Converge cloudserver images

[francoisferrand]

Build federation image as additional layers on top of "standard" cloudserver image, to avoid duplication and ensure the image we tested is used in production.
There are still some differences at the moment (e.g. name of user, path) which should be further converged to minimize differences, may be done over time after considering all things.

This allows us to fully control (and minimize) what gets into the image, relying on any official node image. Also, now switch from python-based supervisord to a golang reimplementation [1], to minimize dependencies and CVEs.

Finally, took the change to fix startup command of the image, to ensure it properly propagates OS signals.

[1] ochinchina/supervisord

Issue: CLDSRV-597

[bert-e]

Hello francoisferrand,

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[bert-e]

Waiting for approval

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.55%. Comparing base (2c8ff15) to head (6f7f399).

Additional details and impacted files

@@               Coverage Diff                @@
##           development/9.0    #5716   +/-   ##
================================================
  Coverage            60.55%   60.55%           
================================================
  Files                  185      185           
  Lines                11617    11617           
================================================
  Hits                  7035     7035           
  Misses                4582     4582           

Flag	Coverage Δ
unit	60.55% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[benzekrimaha]

ARG CLOUDSERVER_VERSION=latest

[benzekrimaha]

COPY --chown=${USER}:0 --from=builder /usr/src/app ${HOME_DIR}/cloudserver