use case insensitive linguistic sort and compare when connecting to oracle

was a cherry pick of https://github.com/owncloud/core/pull/8307 to master, forward port of https://github.com/owncloud/core/pull/8306

now switched to setting the the sort and compare session params when opening the connection.

cc @DeepDiver1975 @icewind1991 @PVince81 @karlitschek