[ox] Add StringView, Writer system, Preloader system

deps/ox/src/ox/model/CMakeLists.txt

@@ -2,6 +2,7 @@ add_library(
 	OxModel
 		desctypes.cpp
 		descwrite.cpp
+		modelvalue.cpp
 )
 
 target_link_libraries(
@@ -42,3 +43,7 @@ install(TARGETS OxModel
         LIBRARY DESTINATION lib/ox
         ARCHIVE DESTINATION lib/ox
 )
+
+if(OX_RUN_TESTS)
+	add_subdirectory(test)
+endif()