Add a MSVC / Windows compatible snprintf function (#7353)

Use sizeof where applicable for mt_snprintf

src/script/cpp_api/s_base.cpp

@@ -293,7 +293,7 @@ void ScriptApiBase::stackDump(std::ostream &o)
 				break;
 			case LUA_TNUMBER:  /* numbers */ {
 				char buf[10];
-				snprintf(buf, 10, "%lf", lua_tonumber(m_luastack, i));
+				porting::mt_snprintf(buf, sizeof(buf), "%lf", lua_tonumber(m_luastack, i));
 				o << buf;
 				break;
 			}