First part of design defined in #140360 Images in PR This PR does two things: - Creates new panel in theme preferences called "Common" that doesn't belong to any editor - Moves "Preview Range" property in common, and removes it from animation editors. Now, there is a single theme property for preview range, rather than 5 for each animation editor. Co-authored-by: Pablo Vazquez <pablo@blender.org> Pull Request: https://projects.blender.org/blender/blender/pulls/140686