redo "Export handshape transcription as CSV..." menu option

[kvesik]

This menu option was implemented before we added the whole concept of modules, so the code to export handconfig csv's is out of date and doesn't work anymore. We do currently have a way to export the full corpus as a json file, but @kchall do we want to update this option so that it's still possible to export handconfig transcriptions only, to csv?

[kchall]

@kvesik Maybe eventually? But it doesn't need to be a priority, because we would still have to figure out how to handle the new modular options, and deal with timing, etc., so it doesn't make sense to do this only for handshapes.

[kvesik]

OK @kchall -- I think what I'll do for now is comment out the relevant code chunks so that the item no longer appears in the File menu (since it doesn't work anyway). And then we can consider potentially reusing them in future.