moved column and table class from namespace sql to query

test/orm/query/GeneratorTests.cpp

@@ -1,15 +1,13 @@
 #include <catch2/catch_test_macros.hpp>
 
 #include "matador/query/generator.hpp"
-
-#include "matador/sql/column.hpp"
+#include "matador/query/column.hpp"
 
 #include "../../models/airplane.hpp"
 #include "../../models/flight.hpp"
 
 using namespace matador::utils;
 using namespace matador::query;
-using namespace matador::sql;
 using namespace matador::test;
 
 TEST_CASE("Test placeholder generator", "[generator][placeholder]") {

test/orm/query/QueryBuilderTest.cpp

@@ -4,11 +4,11 @@
 
 #include <matador/query/criteria.hpp>
 #include <matador/query/query.hpp>
+#include "matador/query/table.hpp"
 
 #include "matador/object/attribute_definition_generator.hpp"
 
 #include "matador/sql/connection.hpp"
-#include "matador/sql/table.hpp"
 
 #include "matador/utils/placeholder.hpp"