FR: Search for part of a filename, case insensitive

[puetsch]

A common use case for me to search a file when knowing part of the filename.

As I understand, this currently is possible using the Marta lookup functionality and entering Name has abc.

1. I find it a bit cumbersome that this common use case requires me to enter keywords. I would like if this was the default behavior for search (instead of searching from the beginning of the filename which I never do). That's assuming I'm not an unusual user but it's actually a common use case, of course.
2. I haven't found a way to search for files that contain "abc" in their filename, case insensitive. Did I miss a function, or is this currently indeed not possible? If not, I'd like that as an added features. (E.g. the lookup dialog could have a check box "case sensitive")