Customes Scene creation from MultiScene.from_files

[gerritholl]

Feature Request

Is your feature request related to a problem? Please describe.

MultiScene.from_files is a helpful classmethod to create a MultiScene from files, creating the Scene objects automagically after grouping files (usually) by time. Currently, it creates Scene objects passing only the filenames argument, such that it's not possible to alter how the Scenes are created or what arguments are passed on to the readers with reader_kwargs.

Describe the solution you'd like

I'd like that MultiScene.from_files takes an additional keyword argument scene_kwargs that will be a mapping of keyword arguments passed to the scene creation.

Describe any changes to existing user workflow

New feature will not break any backward compatibility.

Additional context

This proposes YAND (yet another nested dictionary). It's not pretty, but any other solution would probably require a major overhaul. Currently users who need a MultiScene with better customisation of Scene creation can create their Scene objects separately, then combine them into a MultiScene. This may require duplicating some of the work currently done in MultiScene.from_files.