OGM-612 Add tests for MongoDB
OGM-612 Remove unused parameter
OGM-612 Fix storage of entity with object id and embeddable
OGM-612 Set emebedded columns during insert
OGM-612 Move DOT_SEPARATOR_PATTERN to MongoHelpers
OGM-612 Remove unused MongoHelpers#getValueFromColumns(...)
OGM-612 Misc. improvements: Avoiding regexp for simple properties, moving helper method to only class using it