Support importing raw image files

[cdebonnel]

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

Supporting raw image files would make DataLab more versatile and useful for a broader range of scientific and engineering applications.

Describe the solution you'd like

Add support for importing raw files in the DataLab Import Wizard. Allow users to select raw files in the file dialog.

Describe alternatives you've considered

The user may write a DataLab plugin.