ref: Send frames for all spans

[philipphofmann]

Initially, we wanted to send frame data only for spans started on the main thread, but we decided that the frame data makes sense for all spans. This PR fixes that.

[codecov]

Codecov Report

Merging #3478 (47ae280) into main (ef5821b) will decrease coverage by 0.035%.
The diff coverage is 100.000%.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #3478       +/-   ##
=============================================
- Coverage   89.025%   88.991%   -0.035%     
=============================================
  Files          525       525               
  Lines        56898     56891        -7     
  Branches     20452     20455        +3     
=============================================
- Hits         50654     50628       -26     
- Misses        5322      5343       +21     
+ Partials       922       920        -2     

Files	Coverage Δ
Sources/Sentry/SentrySpan.m	98.395% <100.000%> (ø)
...ests/SentryTests/Transaction/SentrySpanTests.swift	99.404% <100.000%> (-0.002%)	⬇️

... and 19 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ef5821b...47ae280. Read the comment docs.

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1210.27 ms	1227.16 ms	16.89 ms
Size	21.58 KiB	414.92 KiB	393.34 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
8f397a7	1251.82 ms	1268.34 ms	16.52 ms
53a8885	1241.02 ms	1270.66 ms	29.64 ms
5f8ee7a	1253.96 ms	1264.98 ms	11.02 ms
154f795	1225.53 ms	1231.04 ms	5.51 ms
e998fd0	1241.49 ms	1262.63 ms	21.14 ms
05644fe	1244.04 ms	1244.46 ms	0.42 ms
c0ff306	1219.24 ms	1243.96 ms	24.72 ms
7192d9e	1221.86 ms	1248.28 ms	26.42 ms
ef5821b	1253.18 ms	1265.46 ms	12.28 ms
b16d18c	1245.60 ms	1250.94 ms	5.34 ms

App size

Revision	Plain	With Sentry	Diff
8f397a7	20.76 KiB	420.55 KiB	399.79 KiB
53a8885	20.76 KiB	434.65 KiB	413.89 KiB
5f8ee7a	22.85 KiB	411.93 KiB	389.08 KiB
154f795	20.76 KiB	435.25 KiB	414.49 KiB
e998fd0	21.58 KiB	414.59 KiB	393.01 KiB
05644fe	22.85 KiB	408.88 KiB	386.03 KiB
c0ff306	20.76 KiB	434.65 KiB	413.89 KiB
7192d9e	20.76 KiB	431.71 KiB	410.95 KiB
ef5821b	21.58 KiB	414.96 KiB	393.37 KiB
b16d18c	20.76 KiB	437.12 KiB	416.36 KiB

[armcknight]

Looks mostly fine, with one threading question

[armcknight]

Does this need any kind of synchronization now that it's multithreaded?

[armcknight]

@philipphofmann please look into this and open a subsequent PR if necessary.