Feature Request: Set transparency and resolution in Export dialog

Would be a nice UX and user workflow improvement to be able to set the export properties in the export dialogue and not in the preferences beforehand. The latter could be removed or still serve as the default - however it'd be better to retain the last setting in the dialog (as it currently already does for file types).

This is the feature found in many other software and thus an common expectation of first-time users. Otherwise, they do their export, realize this is not what they wanted, go back, search, search, search, google, then find in the handbook that it's a setting buried in preferences, etc.
Also i often find myself in use cases where i want to generate output files with different resolutions or settings one after another. Going back and forth between preferences and export would be an unnecessary kerfuffle.

Not sure if this can easily be done with the standard Qt component (i.e. as an expandable "export settings" section"). If not, could still be done the way e.g. GIMP (and i believe Photoshop) do it, namely showing an options dialog right after hitting OK on the export dialog.

Adding this to #303755: [EPIC] Image export issues