Refactor hex code into individual module
Refactor hex code into individual module

To keep all things related to the Intel Hex format and the MicroPython
details contained in their own modules.

There is no functional changes, just the refactor.

bbcmicrobit/PythonEditor,bbcmicrobit/PythonEditor,bbcmicrobit/PythonEditor,bbcmicrobit/PythonEditor