Can you just put some svg tags around your svg code and get an image?
Topic on Extension talk:NativeSvgHandler
I too am curious how this works. I've tried uploading svg files, embedding <svg>...</svg> payloads directly in the source editor and embedding URIs to remotely hosted svg files, all without any success. LocalSettings.php:
wfLoadExtension('NativeSvgHandler');
$wgFileExtensions[] = 'svg';
Since it is a file handler you need to upload the SVG File. The Handler skips the JPG/PNG-thumbnail-process and delivers instead the SVG in a direct way.
For inline SVG was another extension ..
https://www.mediawiki.org/w/index.php?title=Extension:Inline_SVG_extension&oldid=2490064
it's unmaintained and was sweeped.