feat: Add FileNotFoundError

[romanovacca]

Closes #10640

Currently when reading a non existing file with scan_csv, you get the following error:

exceptions.ComputeError: error open file: example.csv, error open file: example.csv, No such file or directory (os error 2)

Where the error message is also duplicated because of how the error is passed.

After this PR, it looks like:

polars.exceptions.FileNotFoundError: No such file or directory: example.csv

Not sure if the way i have implemented it, is what you meant in the issue @stinodego ? With the way I have set it up now, we could also check for other reading errors such as "Permission Denied" etc, but not sure if you see added value to that.

[stinodego]

Almost what I meant! See my comment to raise the correct error in Python.

[stinodego]

After looking at this a bit more, we have to do things a bit differently. I opened #12355 as a replacement for this one, inspired by the work in this PR.