[Jeehut]

Overview

HorizontalLabeledContentStyle(muteContent:) ignored its parameter and always rendered the content in .secondary. The content is now secondary only when muteContent is true (the default), so nothing changes for callers that don't pass false.

Split out of #7. Adds the small renderedPixels(of:) test helper, which compares two views rendered with ImageRenderer.

How this was verified

HorizontalLabeledContentStyleTests renders the style with muteContent: true and false and compares the pixels with a hand-built reference in .secondary and .primary.

Red, with main's style:

✔ mutedContentIsSecondary()
✘ unmutedContentIsPrimary(): unmuted == renderedPixels(of: self.reference(contentStyle: .primary))
✘ Test run with 2 tests in 1 suite failed with 1 issue.

Green, this branch:

✔ Test run with 2 tests in 1 suite passed.