C++: fix 'find usages' for templates

Fix find usages for template class(class name and template parameters)
or template function(template parameters).

Fixed:
* marking
* find usages
* follow symbol

Change-Id: I22fdbc11260cbd8ee9aafdd76aaeee0f4f49f9fd
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>