internal: Add abnormal mechanism to SentrySession

[philipphofmann]

📜 Description

Add abnormal mechanism to SentrySession, which is required for reporting fatal app hangs, and the app hangs rate. This PR only adds the property, which will only be used in a follow up PR via the ANRIntegration. Currently, the property is unused.

#skip-changelog

💡 Motivation and Context

Required for #3319.

💚 How did you test it?

Unit tests.

📝 Checklist

You have to check all boxes before merging:

• 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.
• I updated the wizard 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 ✅

Project coverage is 92.260%. Comparing base (c1d576a) to head (658a015).
Report is 10 commits behind head on main.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #4842       +/-   ##
=============================================
+ Coverage   92.249%   92.260%   +0.011%     
=============================================
  Files          658       658               
  Lines        77231     77281       +50     
  Branches     27966     27959        -7     
=============================================
+ Hits         71245     71300       +55     
+ Misses        5887      5885        -2     
+ Partials        99        96        -3     

Files with missing lines	Coverage Δ
Sources/Sentry/SentrySession.m	99.512% <100.000%> (+0.019%)	⬆️
Tests/SentryTests/SentrySessionTests.swift	99.346% <100.000%> (+0.289%)	⬆️

... and 9 files with indirect coverage changes

---

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1218.42 ms	1253.49 ms	35.07 ms
Size	22.32 KiB	820.13 KiB	797.81 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
61a1a2b	1222.73 ms	1245.35 ms	22.62 ms
08e12bc	1204.51 ms	1215.98 ms	11.47 ms
65290e0	1204.29 ms	1217.00 ms	12.71 ms
4597906	1228.37 ms	1242.29 ms	13.92 ms
a95ba2f	1223.52 ms	1245.69 ms	22.17 ms
39b1c35	1244.71 ms	1248.60 ms	3.89 ms
2d2068d	1238.02 ms	1249.90 ms	11.88 ms
d257eb9	1206.98 ms	1227.50 ms	20.52 ms
d802ba2	1225.96 ms	1245.37 ms	19.41 ms
3297d6e	1206.80 ms	1213.86 ms	7.06 ms

App size

Revision	Plain	With Sentry	Diff
61a1a2b	21.58 KiB	424.34 KiB	402.76 KiB
08e12bc	21.58 KiB	539.88 KiB	518.30 KiB
65290e0	21.58 KiB	418.76 KiB	397.18 KiB
4597906	21.58 KiB	678.19 KiB	656.61 KiB
a95ba2f	21.58 KiB	706.46 KiB	684.88 KiB
39b1c35	22.85 KiB	408.88 KiB	386.03 KiB
2d2068d	21.58 KiB	729.47 KiB	707.89 KiB
d257eb9	20.76 KiB	433.22 KiB	412.46 KiB
d802ba2	21.90 KiB	708.95 KiB	687.05 KiB
3297d6e	21.58 KiB	418.44 KiB	396.86 KiB

Previous results on branch: internal/session-abnormal-mechanism

Startup times

Revision	Plain	With Sentry	Diff
f108326	1224.31 ms	1244.91 ms	20.61 ms
8827d39	1232.73 ms	1256.76 ms	24.03 ms
54fd31a	1221.27 ms	1234.84 ms	13.57 ms

App size

Revision	Plain	With Sentry	Diff
f108326	22.31 KiB	820.12 KiB	797.81 KiB
8827d39	22.31 KiB	819.63 KiB	797.31 KiB
54fd31a	22.31 KiB	820.13 KiB	797.81 KiB

[armcknight]

Just took a quick look, some comments/questions

[armcknight]

No prob @philipphofmann , looks good now!