Fixed save/load, sfg creating, simulation, bug fixes

Fixed a lot of bug fixes, also added shortcut for creating signal "Space"

src/simulation/compile.cpp

@@ -204,8 +204,8 @@ private:
 			if (bits > 64) {
 				throw py::value_error{"Cannot truncate to more than 64 bits"};
 			}
-			this->add_instruction(instruction_type::truncate, no_result_index, 0).bit_mask = static_cast<std::int64_t>(std::int64_t{1}
-																													   << bits);
+			this->add_instruction(instruction_type::truncate, no_result_index, 0).bit_mask = static_cast<std::int64_t>(
+				(std::int64_t{1} << bits) - 1);
 		}
 	}