[keycloak-dev] Oracle stores an empty string as null

If you try to store an empty string in Oracle it is actually stored as a null [1]. We actually often store empty strings due to the way AngularJS works. An empty input on a form ends up being sent as an empty string rather than a null. This can lead to all sorts of fun issues. For example https://issues.jboss.org/browse/KEYCLOAK-5308. [1] https://stackoverflow.com/questions/13278773/null-vs-empty-string-in-oracle