Don't use using namespace for catch2 tests
When converting cppTango to not have "using namespace" in header files I punted on the tests and therefore we have
using namespace std;
using namespace Tango;
in tests/common.h.
But common.h also holds various other code which is used in all three test frameworks.
I propose to reorganize the code so that the using namespace declarations are not present for the catch2 tests but everything else.
Edited by Thomas Braun