Tracking issue for DevTools related Perfetto requests / bugs

[kenzieschmoll]

bug hotlist: 4148010

• support a dark theme: b/246338404
• Configurable track order from post message API: b/259303986
• register a notifyOnSelected handler in the postMessage api: b/249828626
• overall UI density: added a comment to existing issue feature: UI layout to maximize display of trace events google/perfetto#429
• drag and drop to reorder tracks does not work for tracks in a track group: Can't drag to reorder tracks in track group google/perfetto#472

Early feedback from Dart / Flutter team members:

• timeline start and end time: Timeline start and end time are hard to read for large values. google/perfetto#446
• track overflow issues: Timeline tracks overflow for long names and star button google/perfetto#447
• accessibility: Trace event colors don't meet accessibility requirements google/perfetto#448

Feature requests:

• expand post message API to support expanding all track groups: Expand the post message API to support automatically expanding track groups google/perfetto#748

Labeling as blocked since the fixes will need to happen in perfetto and not devtools.