[SP-1021] Backport of [PDI-7507] Get System Info - Hostname - Returns 127.0.0.1 (5.0)

<h1>DIRECT-MASTER</h1>

* FIX: Added getHostnameReal() method and its invocations
* Refactoring: all SystemData types (96) delivered to enum SystemDataTypes. Changes really simplify work with types (adding,moving)
* Reformat