OFX: Sell types does not include SELLOPT

[naskooskov]

I have been trying to get beancount-import to work for my Fidelity ofx files and found that it doesn't handle selling options short quite correctly. I haven't fully debugged whether it has other issues, but at least the simple one is that it does not consider SELLOPT transaction as a SELL_TYPES member. I'm happy to send patches, but this one almost feels simple enough to add if you think it should be added than the overhead of PR.

[Zburatorul]

@naskooskov A fix for the issue you found would be very welcome. We do PRs even for one-line documentation changes, and this fix warrants some test data as well, so I don't think it's overkill.

[naskooskov]

I have a small enough file from Fidelity that I can use for writing a test. It does a short sell first and an expired option later, which is posted as a transfer. Unfortunately, unless I make bigger and unrelated changes, the journal entries generated by beancount-import are invalid according to bean-check because of included FIXMEs. Adding to the test harness seems to fail if the journal file does not pass bean-check.

Any advice on how to handle adding a test for this case?

P.S. I'm actually adding a bit more code to support options more along the lines of https://groups.google.com/g/beancount/c/iJirO6GOMgU, so it will be a bit more than just adding sellopt support.