ts: refactor OpenCV tests

- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers

modules/core/test/test_utils.cpp

@@ -1,12 +1,9 @@
 // This file is part of OpenCV project.
 // It is subject to the license terms in the LICENSE file found in the top-level directory
 // of this distribution and at http://opencv.org/license.html.
-
 #include "test_precomp.hpp"
 
-using namespace cv;
-
-namespace {
+namespace opencv_test { namespace {
 
 static const char * const keys =
     "{ h help    |       | print help }"
@@ -264,4 +261,4 @@ TEST(AutoBuffer, allocate_test)
     EXPECT_EQ(6u, abuf.size());
 }
 
-} // namespace
+}} // namespace