Add Timeline and ScreenshotAnnotator

[danielmolnar]

New Feature: Timeline and ScreenshotAnnotator

1.) Timeline

Adds the ability to start a Timeline during the test, which can record and print user actions (e.g. tap) as they happen or onError. After the test is finished a HTML overview is generated (for onError and live timeline)

• Included in this PR: act.tap
• More actions will be made recordable with follow up PRs.

Terminal view

HTML view

Bildschirmaufnahme.2024-06-18.um.04.13.53.mov

2.) abstract class ScreenshotAnnotator

While aTimeline is being recorded, annotates screenshots to provide visual information about the location in which a user action took place.

• In this PR: CrosshairAnnotator for act.tap.

Steps:

• Refactor `takeScreenshot``
• Add ScreenshotAnnotator interface
• Add CrosshairAnnotator for act.tap
• Add tests to screenshot_test.dart
• Introduce Timeline
• Create annotated screenshot when act.tap is called during recording
• Create annotated screenshot when act.dragUntilVisible is called during recording
• Add tests for localTimeline
• Add tests for globalTimeline