Missing `svg-document` resource type

In newer Safari versions there's a resource type `svg-document` that we don't take into account:
https://developer.apple.com/documentation/safariservices/creating-a-content-blocker#:~:text=any%20untyped%20load)%2C-,svg%2Ddocument,-%2C%20media%2C

We should test for which requests this resource type is used and then decide which of AdGuard rules content types it should be mapped to.