Support for GNOME 46

[menocheck]

The Functions add and add_actor got removed in GNOME 46.

This fixes the error mentioned in #280

I did not test the changes on GNOME 45 but I guess it should still work.

[jfernandez]

+1

[menocheck]

The function remove_actor also got removed: https://gjs-docs.gnome.org/clutter13/clutter.container#method-remove_actor

gnome-shell[79671]: Extension freon@UshakovVasilii_Github.yahoo.com: TypeError: this.container.get_parent().remove_actor is not a function

Stack trace:
    _positionInPanelChanged@file:///home/menocheck/.local/share/gnome-shell/extensions/freon@UshakovVasilii_Github.yahoo.com/extension.js:207:37
    enable@file:///home/menocheck/.local/share/gnome-shell/extensions/freon@UshakovVasilii_Github.yahoo.com/extension.js:990:25
    _callExtensionEnable@resource:///org/gnome/shell/ui/extensionSystem.js:266:38
    ...

I've updated the commit.