Consolidate all services to use the Reva config struct for the shared package.
This works because all services (except 'notifications', 'thumbnails' and
'webdav') where using the same config keys and environment variables for
setting the reva gateway.
* Use go-micro store to cache the roles
Add custom in-memory implementation
* replace redis with custom etcd implementation
* adjust table name for the cache in the roles manager
* Fix tests
* Fix sonarcloud issues
* Refactor for sonarcloud
* Allow configuration of cache per service
* Reuse parent context in etcd implementation
