Add support for Drag and Drop file loading

[Mhowser]

Is your feature request related to a problem? Please describe.
I have a ton of NIF files that need to be imported into blender, and it is quite slow manually importing each one.

Describe the solution you'd like
Simply click and drop the file into blender

Describe alternatives you've considered
N/A

Additional context
This currently does not work.

[HENDRIX-ZT2]

We can't implement this, blender devs have to support drag and drop first.

[HENDRIX-ZT2]

The only thing we can do is allow for multiple nifs to be selected on import, like we're doing for kf.

[neomonkeus]

Yeah I attempting to find out more if Blender supported associating custom file extensions with addons &/or drag & drop functionality, but they aren't super responsive on blender.chat. Not sure it that is separate to the old IRC chatrooms they have, but I do see lots of devs I recognise, so a bit surprised.

Anyways, there are few items in their backlog, but no real tangible work to enable us to support this request currently.