Allow sorting/filtering by side-car types

[Sandersoni]

Following up with a simplified feature request from an earlier question.
http://forums.camerabits.com/index.php?topic=14730.msg72501#msg72501

In a contact sheet view, I would like to be able to see if a RAW image has been edited/processed.

This usually means (in the absence of a clear universal processing status tag) at least one of the following:

• .dop (dxo photo labs) or .on1 (capture one) side cars are present
• .xmp side car above a certain size (Adobe Camera Raw or Lightroom)

There are more sophisticated and reliable methods, but which would also be more difficult to implement or at risk of becoming obsolete.

1. Allow filtering/sorting by presence of particular side car type as a proxy for editing status.
That way, i would show only my RAWs with .dop sidecars and apply a certain colour label to them = edited.

This could sit in the sort or custom sort dialog ('side car type present') or be part of the filtering.

2. It would be useful if the filename would capture side cars (can be optional)?

• P1187903.RAW+JPG - status quo
• P1187903.RAW+JPG+XMP+DOP - proposed

[Sandersoni]

I have patch worked this for myself for now with an Exiftool batch script.
Tried a Python script as well, but more familiar with Exiftool.

Two lines of code simply; set xmp label to green for ‘RW2’ files that have ‘RW2.dop’ sidecars, and create xmp files and set XMP label to green if XMP sidecar doesn’t exist already.
https://exiftool.org/forum/index.php?topic=13208.0

When i browse my image folders with any third-party darktable browser, all unedited images have red labels and edited/processed images have green labels.