Changes

Improve the pipeline of some Jenkinsfiles to construct a build
version or to release a given version of some projects.

The pipeline for building Docker images are moved into the
releases directory.

Add four new Jenkinsfiles: one for registering a Docker image
for building a Silverpeas project, one for registering a Docker
image for developing on a Silverpeas project, one for preparing
the production-ready Docker image of a version of Silverpeas and
one for creating an IzPack installer of Silverpeas.

The pipeline for releasing a stable version of Silverpeas is
rewritten in the declarative syntax. Instead of doing itself some
jobs (like the Docker images construction or the documentation
generation) it delegates them to external pipelines.

In the pipeline of releasing a version of Silverpeas, split each stage
of release in two: one for the releasing itself and another one for
preparing the dev iteration for the next version of the project.

Improve the pipeline of publishing the community web site by taking into
account the release of a new version of Silverpeas.

The pipeline of publishing the documentation of Silverpeas-Core,
Silverpeas-Components and the community web site for a new version of
Silverpeas is now in declarative syntax and has been improved to take
into account existing Jenkins job (for delegating some of its stages)

The pipeline of releasing a new version of Silverpeas takes care now of
the expectations of the pipeline of publishing Silverpeas projects'
documentation.

Fix a bug when computing the Docker image version from which a container
has to be spawn to running the job making a build version of Silverpeas.

In the Silverpeas release pipeline, add a step of sending a reminder
email about tasks to do after just a release.

Improve the pipeline of publishing the community web site.

Improve the content of the email sent by the pipeline of preparing
the Docker image of Silverpeas for production.

Pipeline to release the Silverpeas SSO library and the Silverpeas Web
Browser Edition library have been rewritten in declarative syntax.

Improve and fix some pipelines

Improve the pipelines about testing the installation and the
upgrade of Silverpeas against different databases. Rewrite
them in the declarative syntax.

Fixing the git repo URL about WBE project.

Fix a bug both in the pipelines of publishing a build version of
Silverpeas SSO and Silverpeas WBE: the setting of the build version was
missing!

Fix another bug with the var version instead of buildVersion in some pipelines
In the pipeline about the WBE project, the Git branch is main and not
master

Fix mispelled pom property name for the Silverpeas Jackrabbit-JCA project
Fix a bug in the pipeline of releasing a Silverpeas Jackrabbit-JCA release.

Fix a bug in the release pipeline of Silverpeas
Fix a bug in the Silverpea doc publishing pipeline
Fix a bug in the izPack installer generator pipeline
Fix a bug in the pipeline of updating the Dockerfile to generate a
Docker image of Silverpeas for the production.
Fix a bug in the pipeline buidling a Docker image of Silverpeas for
testing purpose.