Initial skeleton of event logger
Refactor event filtering
Merge branch 'feature/nc-237' of code.opennodecloud.com:nodeconductor/nodeconductor into feature/nc-237
event formatter format method (nc-237)
event_logger usages (nc-237)
Merge branch 'develop' of code.opennodecloud.com:nodeconductor/nodeconductor into feature/nc-237
Add a placaholder for log configuration (nc-237)
Refactor event records to send only available data
Merge branch 'feature/nc-237' into 'develop'

Feature/nc 237 (event logger)