Accept object for label orientation

[mAAdhaTTah]

Fixes #1234.

This is what it looks like in the demo:

The labels with "bottom" also overlap with the chart when labelOrientation is just "bottom", so this isn't directly related to my changes. Dunno if that's something you want me to fix here or if you have an issue for that.

I had to extract getLabelOrientation cuz ESLint was complaining about function complexity. Also wondering the props types are in "style". Dunno if we should provide a default fallback if people leave out a specific label's orientation? This seemed like the least-invasive implementation though.

[mAAdhaTTah]

Couple things about the test failures:

1. When I ran prettier over the files, I got a lot of additonal changes, that I thought might be better for a separate PR, so I didn't include all of those.
2. It looks like it's also failing on Chromatic, which I don't have a key for. Not sure how you're handling this for outside contributors.

[boygirl]

@mAAdhaTTah sorry for the delay! These changes look good. I've opened a new PR with your changes in order to get chromatic to run. #1256