fix: Use correct rendered frames timestamp

[philipphofmann]

📜 Description

Use the timestamp of the DisplayLink wrapper when a new frame is reported for TTID/TTFD and the app start. This PR is based on #3530.

💡 Motivation and Context

I noticed that the end timestamps of TTID and the app start initial frame render didn't match properly in #3530.

Previously

The duration of the app start and the TTID don't match.

Fixed version

Now they do.

💚 How did you test it?

Unit tests and simulator.

📝 Checklist

You have to check all boxes before merging:

• I reviewed the submitted code.
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (ce54c6a) 89.284% compared to head (79301a8) 89.237%.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #3531       +/-   ##
=============================================
- Coverage   89.284%   89.237%   -0.048%     
=============================================
  Files          528       528               
  Lines        57655     57634       -21     
  Branches     20657     20649        -8     
=============================================
- Hits         51477     51431       -46     
- Misses        5155      5287      +132     
+ Partials      1023       916      -107     

Files	Coverage Δ
SentryTestUtils/TestCurrentDateProvider.swift	82.500% <100.000%> (+0.448%)	⬆️
Sources/Sentry/SentryAppStartTracker.m	97.604% <100.000%> (+0.014%)	⬆️
Sources/Sentry/SentryFramesTracker.m	100.000% <100.000%> (ø)
Sources/Sentry/SentryTimeToDisplayTracker.m	100.000% <100.000%> (ø)
.../AppStartTracking/SentryAppStartTrackerTests.swift	98.492% <100.000%> (+0.011%)	⬆️
...ance/FramesTracking/SentryFramesTrackerTests.swift	99.099% <100.000%> (+0.016%)	⬆️

... and 44 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1199.94 ms	1217.04 ms	17.10 ms
Size	21.58 KiB	418.70 KiB	397.12 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
3437454	1225.64 ms	1234.31 ms	8.67 ms
25bcc50	1233.47 ms	1234.27 ms	0.80 ms
7bb0873	1360.94 ms	1362.24 ms	1.30 ms
e7b566f	1197.49 ms	1229.46 ms	31.97 ms
7bc3c0d	1222.86 ms	1244.90 ms	22.04 ms
326b7eb	1252.86 ms	1259.56 ms	6.70 ms
c78683b	1246.71 ms	1258.70 ms	11.99 ms
5616e0a	1224.12 ms	1249.86 ms	25.74 ms
f715499	1234.26 ms	1259.40 ms	25.14 ms
216bdf9	1193.69 ms	1217.90 ms	24.21 ms

App size

Revision	Plain	With Sentry	Diff
3437454	22.85 KiB	408.87 KiB	386.02 KiB
25bcc50	20.76 KiB	427.22 KiB	406.46 KiB
7bb0873	22.85 KiB	407.09 KiB	384.24 KiB
e7b566f	22.85 KiB	414.80 KiB	391.95 KiB
7bc3c0d	20.76 KiB	427.36 KiB	406.59 KiB
326b7eb	20.76 KiB	432.31 KiB	411.55 KiB
c78683b	20.76 KiB	435.24 KiB	414.48 KiB
5616e0a	22.85 KiB	407.44 KiB	384.59 KiB
f715499	20.76 KiB	427.23 KiB	406.47 KiB
216bdf9	21.58 KiB	418.13 KiB	396.54 KiB

Previous results on branch: fix/rendered-frame-timestamp

Startup times

Revision	Plain	With Sentry	Diff
e5e7fb4	1215.28 ms	1229.82 ms	14.55 ms
e669be6	1225.63 ms	1252.06 ms	26.43 ms

App size

Revision	Plain	With Sentry	Diff
e5e7fb4	21.58 KiB	418.76 KiB	397.17 KiB
e669be6	21.58 KiB	418.70 KiB	397.12 KiB

[brustolin]

LGTM