Replace file_name with filename in Effect kwargs

[hugobuddel]

file_name as a kwarg does seem to work, but it behaves differently from filename. In particular, with file_name the absolute path of the file is used, and with filename the relative path (or well, the actual given path). I have not investigated why.

The reason for harmonizing is that when generating FITS keywords, we'd like to have them to have the filename as it was given by the user or the irdb, not the absolute path where this file happens to be on this particular installation.

Do we perhaps want to force file_name?

E.g. put an assert in data_container.py instead of a fallback: https://github.com/AstarVienna/ScopeSim/blob/36df1767c2b8143a199d085cdf1af181660c058a/scopesim/effects/data_container.py#L63-L64

        if filename is None and "file_name" in kwargs:
            filename = kwargs["file_name"]

to

        assert "file_name" not in kwargs, "Please use filename instead of file_name"

or maybe a deprecation notice would be better.

But that is a ScopeSim problem; this PR is just making the IRDB consistent.

[hugobuddel]

Oh this also makes the quantum_efficiency naming consistent in METIS, which should perhaps not belong in this PR but is fine as far as I'm concerned.

[teutoburg]

Certainly useful to have these kwargs harmonized 👍

And as you mentioned this would pave the way to force more consistency with this in ScopeSim, which is also good.