Fix EZP-20106 remove path identification string awareness from services

This is a proposal for fixing **EZP-20106: Repository is aware of legacy storage specific ezcontentobject_tree.path_identification_string**

Updating ```path_identification_string``` from ContentService::updateContentMetadata() is moved to Legacy Storage ContentHandler::updateMetadata(). As ```path_identification_string``` is really an URL alias string in main languages trasformed using ```urlalias_compat``` transformation group, in order to avoid implementing name schema resolving inside storage, stored URL alias text for location is used as a base for transformation, which should result in a correct ```path_identification_string```.

This made possible to remove Legacy Storage specific calls to UrlAliasHandler::publishUrlAliasForLocation() for updating ```path_identification_string``` from ContentService::updateMetadata().

UrlAliasHandler::publishUrlAliasForLocation() with additional parameter implemented only by Legacy Storage is still used for updating ```path_identification_string``` from other service methods. This parameter can be ignored by future storage engines.

## TODO

- [x] write tests for slug converter