fix(launch profiling): set a new trace origin for app launch profiles

[armcknight]

follows #3635

It was requested to make a new origin for these transactions: #3621 (comment)

I wasn't sure what to do for nameSource, another parameter required on the init I needed to use, so I stuck with custom as that's the default value used in some of the other init implementations.

#skip-changelog

[codecov]

Codecov Report

Attention: 14 lines in your changes are missing coverage. Please review.

Comparison is base (54c5990) 89.167% compared to head (2fdf6e9) 89.221%.

Additional details and impacted files

@@                               Coverage Diff                               @@
##           armcknight/feat/launch-profiling5-cleanup     #3636       +/-   ##
===============================================================================
+ Coverage                                     89.167%   89.221%   +0.054%     
===============================================================================
  Files                                            532       532               
  Lines                                          58659     58675       +16     
  Branches                                       21046     21052        +6     
===============================================================================
+ Hits                                           52305     52351       +46     
+ Misses                                          5309      5289       -20     
+ Partials                                        1045      1035       -10     

Files	Coverage Δ
...entryProfilerTests/SentryAppLaunchProfilingTests.m	100.000% <100.000%> (ø)
Sources/Sentry/Profiling/SentryLaunchProfiling.m	61.290% <44.000%> (-1.673%)	⬇️

... and 14 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1201.39 ms	1210.33 ms	8.95 ms
Size	21.58 KiB	422.62 KiB	401.04 KiB

Baseline results on branch: armcknight/feat/launch-profiling5-cleanup

Startup times

Revision	Plain	With Sentry	Diff
4916322	1211.00 ms	1220.00 ms	9.00 ms
b4dffe4	1205.65 ms	1222.49 ms	16.84 ms

App size

Revision	Plain	With Sentry	Diff
4916322	21.58 KiB	422.53 KiB	400.95 KiB
b4dffe4	21.58 KiB	422.53 KiB	400.95 KiB

Previous results on branch: armcknight/feat/launch-profiling6-trace-origin

Startup times

Revision	Plain	With Sentry	Diff
a66372c	1236.47 ms	1255.33 ms	18.86 ms
990435a	1207.18 ms	1215.37 ms	8.18 ms
3d78f77	1214.04 ms	1223.23 ms	9.19 ms

App size

Revision	Plain	With Sentry	Diff
a66372c	21.58 KiB	422.67 KiB	401.09 KiB
990435a	21.58 KiB	422.67 KiB	401.09 KiB
3d78f77	21.58 KiB	422.67 KiB	401.09 KiB

[philipphofmann]

LGTM