Return a key related to version of connector services and its content

There is a need for TPD to determine if the components delivered within different engines are the same (including the custom components). If TPD can identify this by a key, it would be possible to pair this key with the list of available components in the application cache and then to reduce the time to display processor's modale in pipeline designer (as we currently call the content for each engine id).

Currently, environment ressources return a key related to the version of connectors service. If environment ressources could return another key related to the version of connectors and the content of custom components (defined using a hash for example), the service /processing/engines/{engineId} would be able to return a key related to those informations. TPD will then call this endpoint.