Add a check to prevent committing UITest specific configurations

We introduced with Docker test an annotation UITest for integration test on which we can specify the configuration to be executed (servlet engine, database, etc, see: https://dev.xwiki.org/xwiki/bin/view/Community/Testing/DockerTesting/). If this is quite useful for dev, we should never commit those configurations, since then they cannot be overridden to test multiple different configurations. (see: https://github.com/xwiki/xwiki-platform/commit/6578f5f4e4a1b91461e096c36de339c6eb5f4ce9 for an example of such commit).

We could provide a new check with Spoon to detect this in our build. I think we should prevent committing with the following values:

• servletEngine (except if forbiddenEngine is set, cf OfficeImporterIT)
• database
• browser