Port all dbus server/client to to zbus

Seems to generally be working well. May still need a few fixes.

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "pop-cosmic-panel"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 license = "LGPL-3.0-or-later"
 
 [dependencies]
@@ -9,15 +9,21 @@ cascade = "1"
 chrono = "0.4"
 byte_string = "1"
 derivative = "2"
+enumflags2 = "0.7"
+futures = "0.3"
+futures-channel = "0.3"
 gdk4-x11 = "0.3"
 gdk4-wayland = { version = "0.3", optional = true }
 gtk4 = "0.3"
 gobject-sys = "0.14.0"
 libcosmic = { git = "https://github.com/pop-os/libcosmic" }
 once_cell = "1"
+serde = "1"
 toml = "0.5"
 x11 = { version = "2", features = ["xlib"] }
-zbus = "1"
+zbus = "2"
+zbus_names = "2"
+zvariant = "3"
 
 [features]
 layer-shell = ["gdk4-wayland", "libcosmic/layer-shell"]