Allow SVG files to have previews in the File Browser. Adds
nanosvgrast.h to extern\nanosvg\, which is an SVG rasterizer that is
an optional part of the nanosvg source.
Pull Request: https://projects.blender.org/blender/blender/pulls/109567
The library has some modifications and it has been included in a diff.
Reviewed By: campbellbarton
Differential Revision: https://developer.blender.org/D12142
(Some minor changes done in the patch)
Harley Acheson
Dalai Felinto
Antonio Vazquez