Add an internal option to skip Native Animated frames while inactive

[zeyap]

Summary:
This is to investigate a crash on ios in C++ Animated rollout.

On iOS, Native Animated drives frames from a CADisplayLink on the main run
loop. While the app is inactive — which includes the whole
UIApplicationWillEnterForeground → UIApplicationDidBecomeActive transition
— it is not presenting, so a frame rendered then is never seen. Its commit and
synchronous per-view updates still run on the main thread though, competing
with the work the app must complete to become responsive.

Adds initWithSkipFramesDuringForegroundTransition: to
RCTAnimatedModuleProvider, declared in a new
RCTAnimatedModuleProvider+Private.h. When YES, _onDisplayLinkTick returns
early while applicationState == UIApplicationStateInactive.

The public API is unchanged. RCTAnimatedModuleProvider.h is untouched and
the C++ API snapshots have no delta — +Private.h is in the ReactApple
exclude_patterns. Plain init still exists and defaults to NO, so every
existing caller is unaffected; only hosts that opt in via the private header see
different behaviour.

Two properties worth being explicit about:

• The clock is not stopped, only the frame is skipped. AnimationDriver
  computes progress from a timestamp
  (timeDeltaMs = frameTimeMs - startFrameTimeMs_), so the first frame after
  activation resolves to the value the animation should have reached rather
  than resuming from where it was suspended.
• Frames are not skipped while backgrounded — Background is not
  Inactive. Completion handlers, and any app logic they drive, are therefore
  delayed by at most the length of the transition, not by the time spent in the
  background.

Reading applicationState rather than tracking lifecycle notifications also
avoids a failure mode: a mirrored flag must be cleared on every path out of the
transition, including an abandoned foregrounding (a willEnterForeground with
no following didBecomeActive), or frames are skipped indefinitely. There is no
such state to get stuck here.

UIApplicationStateInactive also covers other non-presenting moments — Control
Center, the app switcher, an incoming call banner. Skipping frames there is
harmless for the same reason: the clock keeps running and the first frame after
activation is correct.

The check sits inside the file's existing TARGET_OS_OSX guard, since
UIApplication is iOS-only and this translation unit also builds for macOS.

Changelog:
[Internal]

Reviewed By: javache, christophpurrer

Differential Revision: D118188111

[meta-codesync]

@zeyap has exported this pull request. If you are a Meta employee, you can view the originating Diff in D118188111.

[meta-codesync]

This pull request has been merged in 3f9f385.