Move dbms to database

Summary:
There was only two files in dbms directory so I moved them to database
directory.

Reviewers: buda

Reviewed By: buda

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D540

tests/unit/query_plan_create_set_remove_delete.cpp

@@ -11,7 +11,7 @@
 #include "gtest/gtest.h"
 
 #include "communication/result_stream_faker.hpp"
-#include "dbms/dbms.hpp"
+#include "database/dbms.hpp"
 #include "query/context.hpp"
 #include "query/exceptions.hpp"
 #include "query/interpret/frame.hpp"