Fixing location of User-Settings.json and user servers.pvsc
- Using pqSettings location to provide User Setting path in pqCoreUtilities::getParaViewUserDirectory()
- Emulating QSettings use of XDG_CONFIG_HOME in vtkInitializationHelper::GetUserSettingsDirectory()
- Use of pqCoreUtilities::getParaViewUserDirectory in pqServerConfigurationCollection::userServers()