Move colors and sizing modules out of space_editor_tabs

[rewin123]

Part of #267

Introduced a new trait responsible for ui styling

/// This trait use to get tab style
pub trait TabStyle: Resource {
    fn error_color(&self) -> egui::Color32;
    fn set_egui_style(&self, world: &World, style: &mut egui::Style);
    fn text_size(&self, world: &World) -> f32;

    fn collect_style(&self, world: &World) -> CollectedStyle {
        let error_color = self.error_color();
        let text_size = self.text_size(world);
        CollectedStyle {
            error_color,
            text_size,
        }
    }
}

And getter for style trait can be registered in ui

/// This resource contains registered editor tabs and current dock tree state
#[derive(Resource)]
pub struct EditorUi {
    pub registry: HashMap<TabNameHolder, EditorUiReg>,
    pub tree: egui_dock::DockState<TabNameHolder>,
    pub style_getter: fn(&World) -> &dyn TabStyle,
}

Based on this trait style collecting and pass into dock ui

/// This system use to show all egui editor ui on primary window
/// Will be useful in some specific cases to ad new system before/after this system
pub fn show_editor_ui(world: &mut World) {
    let Ok(egui_context) = world
        .query_filtered::<&mut EguiContext, With<PrimaryWindow>>()
        .get_single(world)
    else {
        return;
    };
    let mut egui_context = egui_context.clone();
    let ctx = egui_context.get_mut();
    egui_extras::install_image_loaders(ctx);

    {
        // set style for editor
        let editor_ui = world.get_resource::<EditorUi>().unwrap();
        let tab_style = (editor_ui.style_getter)(world);
        ctx.style_mut(|stl| {
            tab_style.set_egui_style(&world, stl);
        });
    }

    world.resource_scope::<EditorUi, _>(|world, mut editor_ui| {
        editor_ui.ui(world, ctx);
    });
}

DoublePanel enum variants were renamed

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 93 lines in your changes are missing coverage. Please review.

Project coverage is 34.37%. Comparing base (353b413) to head (17cb142).
Report is 4 commits behind head on v0.6.

Files	Patch %	Lines
crates/editor_ui/src/editor_style.rs	0.00%	29 Missing ⚠️
crates/editor_tabs/src/lib.rs	0.00%	27 Missing ⚠️
crates/editor_tabs/src/tab_style.rs	0.00%	20 Missing ⚠️
crates/editor_tabs/src/tab_viewer.rs	0.00%	8 Missing ⚠️
crates/editor_tabs/src/start_layout.rs	0.00%	6 Missing ⚠️
crates/editor_ui/src/ui_plugin.rs	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             v0.6     #274      +/-   ##
==========================================
- Coverage   34.57%   34.37%   -0.20%     
==========================================
  Files          67       69       +2     
  Lines        9418     9471      +53     
==========================================
  Hits         3256     3256              
- Misses       6162     6215      +53     

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