Implement extension support

[d-e-s-o]

It would be really nice to add extension support to the application. What I mean by that is basically having a way to write scripts/programs that can be invoked as an apcacli sub-command, similar to how you can write git or cargo sub-commands.

We have written something like that for nitrocli. From my perspective, most of that could be copied to apcacli. A discussion thread with most of the design discussions is d-e-s-o/nitrocli#50 (though not everything is applicable) and the main part of the implementation d-e-s-o/nitrocli#112 (likely more relevant). I don't recall all the details off the top of my head, so I don't know exactly how much is transferable and whether there needs to be some design work.

Anyway, this would be really nice to have and would allow us to move functionality that is currently stand-alone into the repository. E.g., I have a program that is useful for mostly manual trading, which basically ensures that stop orders are present for all positions that are above a certain percentage gain (which I see I haven't even published yet).

[d-e-s-o]

Closed by 92b0e2c.