Don't allow non-elementary namespace apps to access desktop integration dbus API

[danirabbit]

Problem

I was just reviewing https://github.com/leolost2605/detective/compare/1.0.2...1.1.0 and third party apps being able to do things like ask for focus or get a list of windows is re-introducing security problems from X11

Proposal

We should make sure that only io.elementary namespace IDs are able to access this dbus interface. Apps shouldn't be able to get this kind of information without user consent

Prior Art (Optional)

No response