feat(gui): add the komorebi-gui debug tool

This commit adds the komorebi-gui debug tool build with egui and eframe.

This tool was built from scratch in a YouTube mini-series which can be
found here: https://www.youtube.com/watch?v=zZKjBMt4kZ4

The most interesting part of this tool right now is the ability to view
debug information about each window as it goes through the rules engine.

While it's possible to change runtime configuration options with this
tool, it is not yet possible to write those changes out to the
configuration file.

komorebi/src/window_manager.rs

@@ -37,6 +37,7 @@ use komorebi_core::OperationBehaviour;
 use komorebi_core::OperationDirection;
 use komorebi_core::Rect;
 use komorebi_core::Sizing;
+use komorebi_core::StackbarLabel;
 use komorebi_core::WindowContainerBehaviour;
 
 use crate::border_manager;
@@ -47,6 +48,7 @@ use crate::load_configuration;
 use crate::monitor::Monitor;
 use crate::ring::Ring;
 use crate::stackbar_manager::STACKBAR_FOCUSED_TEXT_COLOUR;
+use crate::stackbar_manager::STACKBAR_LABEL;
 use crate::stackbar_manager::STACKBAR_MODE;
 use crate::stackbar_manager::STACKBAR_TAB_BACKGROUND_COLOUR;
 use crate::stackbar_manager::STACKBAR_TAB_HEIGHT;
@@ -122,6 +124,7 @@ pub struct GlobalState {
     pub border_offset: i32,
     pub border_width: i32,
     pub stackbar_mode: StackbarMode,
+    pub stackbar_label: StackbarLabel,
     pub stackbar_focused_text_colour: Colour,
     pub stackbar_unfocused_text_colour: Colour,
     pub stackbar_tab_background_colour: Colour,
@@ -164,6 +167,7 @@ impl Default for GlobalState {
             border_offset: border_manager::BORDER_OFFSET.load(Ordering::SeqCst),
             border_width: border_manager::BORDER_WIDTH.load(Ordering::SeqCst),
             stackbar_mode: STACKBAR_MODE.load(),
+            stackbar_label: STACKBAR_LABEL.load(),
             stackbar_focused_text_colour: Colour::Rgb(Rgb::from(
                 STACKBAR_FOCUSED_TEXT_COLOUR.load(Ordering::SeqCst),
             )),