Add wxDocManager::FindTemplate() method.

This allows to find the template corresponding to the document of the given
class.

Closes #12170.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65915 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/docview.h

@@ -414,6 +414,9 @@ public:
     void AssociateTemplate(wxDocTemplate *temp);
     void DisassociateTemplate(wxDocTemplate *temp);
 
+    // Find template from document class info, may return NULL.
+    wxDocTemplate* FindTemplate(const wxClassInfo* documentClassInfo);
+
     wxDocument *GetCurrentDocument() const;
 
     void SetMaxDocsOpen(int n) { m_maxDocsOpen = n; }