tests: add proper catch2 handling

Add proper catch2 support:
 - add catch2 as a submodule
 - add cmake function to add test easily
 - discover each test in test binary
 - remove copies of catch.hpp
 - do not try to process tests for rt1051

Do not test internals of utf8, only public interface (nasty bugs could
occur otherwise).

Signed-off-by: Marcin Smoczyński <smoczynski.marcin@gmail.com>

module-db/tests/QueryInterface.cpp

@@ -1,11 +1,13 @@
+#include <catch2/catch.hpp>
+
 #include "Common/Query.hpp"
 #include "Databases/ContactsDB.hpp"
+#include "Database/Database.hpp"
 #include "Databases/SmsDB.hpp"
 #include "SMSRecord.hpp"
 #include "ThreadRecord.hpp"
-#include "catch.hpp"
-#include "../Database/Database.hpp"
 #include "queries/sms/QuerySMSSearch.hpp"
+
 #include <memory>
 
 namespace db