Document: Enable support for SVG preview

[Inogeo]

Is your feature request related to a problem? Please describe. I use geonode's documents to store SVG symbols and use them in my layer styles (using the direct link to the file uploaded:) However the preview and the thumbnail are not available (see the screenshot below), even if the direct link works properly:

Describe the solution you'd like Enable:

• Preview capacity for *.svg documents
• Thumbnail creation for *.svg documents

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.