Editor code: tidy up BOOLs,NULLs and overrides pt5. (#2876)

A few 'typedefs' replaced by 'using's
This shouldn't have any functional changes at all, just c++17 modernization
It's a part 5 of a split #2847

Signed-off-by: Nemerle <nemerle5+git@gmail.com>

Co-authored-by: Nemerle <nemerle5+git@gmail.com>

Code/Editor/ErrorReportTableModel.cpp

@@ -105,7 +105,7 @@ void CErrorReportTableModel::setErrorReport(CErrorReport* report)
     {
         m_errorRecords.clear();
     }
-    if (report != 0)
+    if (report != nullptr)
     {
         const int count = report->GetErrorCount();
         m_errorRecords.reserve(count);