Add support for compressing/decompressing SVGZ files

[qzu04435]

Feature Suggestion

Hi, and thanks for the great work on this project!

I was wondering if it might be useful to have a mode that allows decompressing .svgz to .svg, and also compressing .svg back to .svgz.

I think such a feature could be convenient in certain workflows.
For example, if the app could ask what to do when dropping .svg or .svgz files—like whether to compress to .svgz or zip the file—that would be really helpful.

Just an idea—thanks for considering it!