Update to 0.4.3, compile it with more features and add CB plugin

Motivation for this change

Update to 0.4.3, add the CB plugin and compile it with more features. I think many of the features (e.g. sqlite and manpages) where before enabled by default, but in newer releases zathura is using meson and making the features more configurable.

I commented the seccomp feature because if enabled, zathura returns an error when you try to open a link (it uses xdg-open). Not sure how to fix it, nor what seccomp does.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.