Open a TXT file containing paths as a gallery

[JonasVerbickas]

I have this feature implemented locally. If you're down to merge it I will clean up my code and submit a pull request.

Feature Description

Currently, when a folder is right-clicked in the file explorer an option to open it in gallery view pops up.
I think TXT files should have an option to be opened as an image gallery as well. (It might make sense to make this not enabled by default)

Example snippet from such a TXT file:

/path/to/dir/a/0.jpg
/path/to/dir/b/11.jpg

Why?

I'm working with the YOLOv8 model, which accepts TXT files containing images as training data.
Each TXT contains paths to images from multiple different directories.
When iteratively changing my dataset I find it useful to preview images to make sure the dataset is diverse quickly.

[fanurs]

@JonasVerbickas Thanks for suggesting this feature and offering to help implement it. Your idea seems particularly useful for handling image datasets, and I can see how it would be beneficial for others as well.

Please go ahead and submit a draft PR with your current implementation, no worries if the code isn't fully cleaned up yet. It'll give us a good starting point to understand its potential impact and make any necessary adjustments. I'm on board with not enabling this feature by default to keep things streamlined for all users.