OGM-428 Simplifying retrieval of option values set via configuration properties

* Providing access to options set via config properties through `OptionsService`; This avoids custom merging of options set via property and options in the dialects (see the code removed in _mongodb_)
* Caching the effectively applying option value for an option on the property/entity/global level after the first retrieval, avoiding the previously done repeated iteration through super-classes in `OptionContextImpl`