Allow .svg upload for images in media library and image user template blocks

[sverraest]

Type

• Enhancement

Problem description

Cannot upload SVG files for image user templates or using media library

Steps to reproduce

Go to media library or add image to user template, attempt to upload .svg

Expected behavior / Proposed solutions

Allow configuration of file upload extensions / mimetype

[Sellato]

I think it's impossible :( Fork CMS is using Fine Uploader, but Fine Uploader is dead.

Fine Uploader is shutting down

So, no SVG, no WEBP and so on.
It's will be great if I'm wrong :)

[carakas]

feel free to create a PR that could solve this

[sverraest]

I've solved this in a hack-ish way, will see if I can improve.
Biggest issue is that there's no point in resizing a .svg which seems to be linked to the image upload.