fix(client): Fix attachment processor dropping additional attachments

[philprime]

📜 Description

Changes the attachment processors to reuse the output of previous integrations, to not drop attachments.

💡 Motivation and Context

When enabling the options attachScreenshot and attachViewHierarchy, the two respective integrations SentryScreenshotIntegration and SentryViewHierarchyIntegration are installed respectively.

The current implementation of the [SentryClient processAttachmentsForEvent:attachments:] is simply replacing the processedAttachments containing the output of the previous integration, instead of merging the result, therefore only one integration can be used at a time.

This PR changes the loop to call each processor with the output of previous ones. This allows processors to add and remove attachments of previous processors. This also introduces an implicit order of integrations based on the installation order in SentryOptionsInternal.m.

We are ignoring this order for now, as we only have two integrations processing attachments, and they are both only adding attachments to the result. I added a note in the code for this.

💚 How did you test it?

TBD

📝 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.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.726%. Comparing base (073562b) to head (dca5a8c).
⚠️ Report is 6 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #5989       +/-   ##
=============================================
+ Coverage   86.672%   86.726%   +0.054%     
=============================================
  Files          424       424               
  Lines        36714     36713        -1     
  Branches     17363     17364        +1     
=============================================
+ Hits         31821     31840       +19     
+ Misses        4846      4827       -19     
+ Partials        47        46        -1     

Files with missing lines	Coverage Δ
Sources/Sentry/SentryClient.m	98.936% <100.000%> (+0.001%)	⬆️
Sources/Sentry/SentryScreenshotIntegration.m	91.836% <100.000%> (-0.321%)	⬇️

... and 11 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1229.85 ms	1255.11 ms	25.25 ms
Size	23.75 KiB	927.08 KiB	903.33 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
c5bedc0	1203.83 ms	1236.17 ms	32.33 ms
aadbffe	1228.73 ms	1251.59 ms	22.86 ms
2de3f92	1207.56 ms	1234.96 ms	27.40 ms
ed85746	1231.79 ms	1248.55 ms	16.75 ms
21efa18	1227.73 ms	1250.04 ms	22.31 ms
7148f97	1235.09 ms	1258.07 ms	22.98 ms
d0f70ce	1226.54 ms	1247.04 ms	20.50 ms
5bf2b17	1213.53 ms	1238.54 ms	25.01 ms
1339919	1214.82 ms	1238.98 ms	24.16 ms
2a36c3f	1227.27 ms	1246.89 ms	19.63 ms

App size

Revision	Plain	With Sentry	Diff
c5bedc0	23.75 KiB	920.63 KiB	896.89 KiB
aadbffe	23.75 KiB	912.77 KiB	889.02 KiB
2de3f92	23.75 KiB	919.69 KiB	895.94 KiB
ed85746	23.75 KiB	920.83 KiB	897.08 KiB
21efa18	23.75 KiB	919.70 KiB	895.95 KiB
7148f97	23.75 KiB	854.78 KiB	831.03 KiB
d0f70ce	23.75 KiB	913.09 KiB	889.34 KiB
5bf2b17	23.75 KiB	913.27 KiB	889.52 KiB
1339919	23.75 KiB	919.70 KiB	895.95 KiB
2a36c3f	23.75 KiB	874.45 KiB	850.71 KiB

Previous results on branch: philprime/fix-attachment-processing

Startup times

Revision	Plain	With Sentry	Diff
6c9100d	1239.02 ms	1263.27 ms	24.24 ms
0421faf	1223.55 ms	1247.63 ms	24.08 ms

App size

Revision	Plain	With Sentry	Diff
6c9100d	23.74 KiB	926.48 KiB	902.73 KiB
0421faf	23.75 KiB	926.72 KiB	902.96 KiB

[itaybre]

LGTM