Allow any note-type with a Gid field, not just the single pre-ordained note-type

[ELLIOTTCABLE]

My language cards use a bunch of different note types for different purposes, with different fields and generated-cards:

Skimming the code, it doesn't look like this addon needs to know anything about the existing card's note-type — just whether it exists. I took a brief stab at patching this, but I couldn't quite get a Python dev-environment setup within my allocated time. 😅

This should only require patching the following to use the field's name, instead of its index, to find the gid:

https://github.com/JASchilz/AnkiSyncDuolingo/blob/2c712177f0daff0e4332d3513735c1602e9f9b26/duolingo_sync/plugin.py#L42-L44

(Ideally, in the process, it'd be nice to have the field renamed to "Duolingo GID" or something clearer, too.)