AT:

• the exists an Optimize commons module that is used by backend, upgrade and reimport-preparation modules
• the Elasticsearch Rest Client is added to the commons module
• the index settings are added to the commons module
• the configuration service is added to the commons module
• the logging loading is added to the commons module

Context:
We use a lot of shared classes/resources throughout the several Optimize modules. For each, we need to add the whole back-end as a dependency, which is totally overkill. Let's have a shared library that contains the important stuff.