Simplified ui method of PaneBehavior

src/ui/app.rs

src/ui/panes.rs

src/ui/panes/default.rs

src/ui/panes/messages_viewer.rs

src/ui/panes/pid_drawing_tool.rs

src/ui/panes/plot.rs

src/ui/panes/valve_control.rs

src/ui/utils.rs

src/ui/widget_gallery.rs