* Fix issue where UIGraphicsRendererFormat is mutated
As part of https://github.com/TextureGroup/Texture/pull/1629, we use the
preferred or default UIGraphicsRendererFormat. This was pointing to a
static variable which content scale was mutated across several graphic
render passes and lead to pixelated views.
* Update reference images with iOS 10.3
- Adding experiment to propagate older trait collections when trait
collections change
- Re-render nodes when user interface style changes (dark mode)
- Snapshot testing examples for dark mode
- Fixes for applying trait collection overrides in XCTest
- Create new define for gating Xcode 11 / iOS 13 features until CI is running it