Add hide/unhide and lock/unlock icons for Inkscape

[choosingausernameishard]

Here’s how they look in context:

[danirabbit]

Thanks for submitting your branch! Can you please submit two separate branches for the lock/unlock symlinks and the hidden/visible icons? It would help keep the commit history cleaner and be easier to review to not lump together different metaphors

We have an unlocked icon already in status called changes-allow. I'm happy with adding more symlinks to the existing icon, but I don't want to have two separate unlocked icons. If you want to propose changes to the "unlocked" icon, I think I'd also like to see separate branches for proposing design changes vs adding symlinks

[choosingausernameishard]

I have now split this PR into three different pull requests, as requested:

• Add symlinks for Inkscape lock/unlock icons #1370
• Add hide/unhide icons for Inkscape #1371
• Redesign changes-allow #1372

I had also submitted another Inkscape-related pull request. Let me know if it should be split as well:

• Inkscape tool icons #1368