LicenseTemplate: Use macro expansion

Convert existing licensetemplate syntax to macro expansion. That
is way more powerful than what we used to have.

Do return the (converted) license template and do not try to fill
in information since that is not available when querying the
template.

Change-Id: Ia4f45ccf055772b21b0c2ce3c083cf49c45ae7d8
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cpptools/cppfilesettingspage.h

@@ -65,7 +65,7 @@ struct CppFileSettings
 
     // Convenience to return a license template completely formatted.
     // Currently made public in
-    static QString licenseTemplate(const QString &file = QString(), const QString &className = QString());
+    static QString licenseTemplate();
 
     bool equals(const CppFileSettings &rhs) const;
     bool operator==(const CppFileSettings &s) const { return equals(s); }