Do not construct settings/resource paths from QSettings object

These paths are controlled by ICore.

Add ICore::installerResourcePath() to replace constructions with
settings(SystemScope)
Replace constructions with settings()->fileName() by usage of
ICore::userResourcePath().

Change-Id: I5a9fa9d09f2563c39dc5d11a4586da825c62f9ac
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/coreplugin/icore.cpp

@@ -421,6 +421,12 @@ QString ICore::userResourcePath()
     return urp;
 }
 
+QString ICore::installerResourcePath()
+{
+    return QFileInfo(settings(QSettings::SystemScope)->fileName()).path() + '/'
+           + Constants::IDE_ID;
+}
+
 QString ICore::documentationPath()
 {
     return QDir::cleanPath(QCoreApplication::applicationDirPath() + '/' + RELATIVE_DOC_PATH);