Utils: Introduce case friendly comparison function to stringutils

Use this operator in the miniprojecttargetselector as well as the
projectconfigurationmodel. This should unify the sorting of
build-/deploy- and runconfigurations in various places in Creator.

Task-number: QTCREATORBUG-20023
Change-Id: I7aed2ebcb9d65244395d68b7dc5da599d6503962
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/stringutils.cpp

@@ -367,4 +367,12 @@ QTCREATOR_UTILS_EXPORT int parseUsedPortFromNetstatOutput(const QByteArray &line
     return port;
 }
 
+int caseFriendlyCompare(const QString &a, const QString &b)
+{
+    int result = a.compare(b, Qt::CaseInsensitive);
+    if (result != 0)
+        return result;
+    return a.compare(b, Qt::CaseSensitive);
+}
+
 } // namespace Utils