T20: Debug

- DebugToolbar, BreakpointList, CallStack with folded library frames, ThreadList
- VariablesPanel and WatchPanel, colored by kind, changes washed
- HexViewer at a base address with the byte under the pointer lit on both sides
- Disassembly with source lines, registers and numbers colored, gutter breakpoints
- Flamegraph that zooms by frame, TimelineProfiler that zooms and pans by wheel
- NetworkInspector with a waterfall, a filter and a request's headers and body
- icons: redo-dot, arrow-down-to-dot, arrow-up-from-dot
- gallery: the Debug page

examples/gallery/pages/mod.rs

@@ -1,6 +1,7 @@
 mod buttons;
 mod charts;
 mod data;
+mod debug;
 mod editor;
 mod feedback;
 mod finance;
@@ -53,6 +54,7 @@ pub const ALL: &[Page] = &[
     editor::PAGE,
     terminal::PAGE,
     git::PAGE,
+    debug::PAGE,
     theme::PAGE,
 ];