Function `strip_data_outline_params_set()` was simplified, so setting
color and outline parameters are not mixed and overwriting as code flows
and so the function is better readable.
Shader code is changed, so that when strip overlaps other strip, it gets
2 px red outline regardless of whether it is active or selected. This
makes it more consistent when strip is not active or selected.
Pull Request: https://projects.blender.org/blender/blender/pulls/124442
af1a6d048d