Add _beginSection and _endSection JSI bindings for systraces

[tomekzaw]

Summary

This PR adds _beginSection and _endSection JSI bindings in worklet runtimes (e.g. Reanimated UI runtime) that begin and end systrace sections, respectively, both on Android and iOS.

Usage:

scheduleOnUI(() => {
  globalThis._beginSection('systrace name here');
  // your code here
  globalThis._endSection();
});

Android Profiler:

Xcode instruments:

For profiling the RN runtime you can use Systrace from react-native (docs).

Test plan