moved schema to query namespace

source/orm/CMakeLists.txt

@@ -1,6 +1,5 @@
 add_library(matador-orm STATIC
   ../../include/matador/orm/error_code.hpp
-  ../../include/matador/orm/schema.hpp
   ../../include/matador/orm/session.hpp
   ../../include/matador/orm/session_query_builder.hpp
   ../../include/matador/query/attribute_string_writer.hpp
@@ -58,6 +57,7 @@ add_library(matador-orm STATIC
   ../../include/matador/query/query_intermediates.hpp
   ../../include/matador/query/query_part.hpp
   ../../include/matador/query/query_utils.hpp
+  ../../include/matador/query/schema.hpp
   ../../include/matador/query/table.hpp
   ../../include/matador/query/value_extractor.hpp
   ../../include/matador/sql/abstract_sql_logger.hpp
@@ -86,7 +86,6 @@ add_library(matador-orm STATIC
   ../../include/matador/sql/statement.hpp
   orm/error_code.cpp
   orm/query_builder_exception.cpp
-  orm/schema.cpp
   orm/session.cpp
   orm/session_query_builder.cpp
   query/attribute_string_writer.cpp
@@ -139,6 +138,7 @@ add_library(matador-orm STATIC
   query/query_compiler.cpp
   query/query_part.cpp
   query/query_utils.cpp
+  query/schema.cpp
   query/table.cpp
   query/value_extractor.cpp
   sql/backend_provider.cpp