With selected strips, it is not clear where one of them begins and another
ends since their outlines are right next to each other.
This changes strip look so that:
- All strips have consistent dark 1pt outline at the outer edge.
- Selected strips have 2pt highlight inside said outer edge.
- Selected strips also have a 1pt wide 33% opacity darker line inside the
selection highlight (and inside possible handles). To improve readability
in case strip content happens to be similar to selection/active color.
Images in PR.
Pull Request: https://projects.blender.org/blender/blender/pulls/123431
b76a95b8b4