refactor: clean up debug image extractor

[vaind]

📜 Description

A little refactoring/cleanup based on the changes I've done in parallel in the windows native support PR (#2286)

💡 Motivation and Context

💚 How did you test it?

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

- clean up debug image extractor ([#2294](https://github.com/getsentry/sentry-dart/pull/2294))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description.

Generated by 🚫 dangerJS against 8b63444

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.01%. Comparing base (fe6dcac) to head (8b63444).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2294   +/-   ##
=======================================
  Coverage   88.01%   88.01%           
=======================================
  Files         247      247           
  Lines        8608     8577   -31     
=======================================
- Hits         7576     7549   -27     
+ Misses       1032     1028    -4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

Android Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	457.57 ms	512.90 ms	55.32 ms
Size	6.49 MiB	7.55 MiB	1.06 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
cfa25fc	351.73 ms	427.65 ms	75.92 ms
4ad2751	374.58 ms	462.00 ms	87.42 ms
613760b	373.42 ms	399.33 ms	25.92 ms
b49bf00	323.46 ms	375.35 ms	51.89 ms
0be962b	325.54 ms	382.83 ms	57.29 ms
ae02632	309.16 ms	348.98 ms	39.82 ms
c3e6c82	392.63 ms	440.76 ms	48.12 ms
21562c5	304.31 ms	348.91 ms	44.61 ms
211a7aa	324.19 ms	393.26 ms	69.07 ms
8cb6557	321.20 ms	370.46 ms	49.26 ms

App size

Revision	Plain	With Sentry	Diff
cfa25fc	6.33 MiB	7.30 MiB	987.47 KiB
4ad2751	6.16 MiB	7.14 MiB	1010.86 KiB
613760b	5.94 MiB	6.92 MiB	1005.98 KiB
b49bf00	6.06 MiB	7.10 MiB	1.04 MiB
0be962b	6.06 MiB	7.03 MiB	990.29 KiB
ae02632	5.94 MiB	6.95 MiB	1.01 MiB
c3e6c82	6.33 MiB	7.26 MiB	950.19 KiB
21562c5	6.16 MiB	7.13 MiB	1001.31 KiB
211a7aa	6.06 MiB	7.03 MiB	997.24 KiB
8cb6557	6.06 MiB	7.03 MiB	997.01 KiB

[github-actions]

iOS Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1264.71 ms	1282.55 ms	17.84 ms
Size	8.38 MiB	9.74 MiB	1.36 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
d8f5abb	1237.73 ms	1259.13 ms	21.39 ms
f275487	1291.65 ms	1339.92 ms	48.26 ms
fcd1ee4	1247.18 ms	1251.35 ms	4.16 ms
f7f46dc	1285.82 ms	1315.06 ms	29.24 ms
ba9c106	1241.76 ms	1265.15 ms	23.40 ms
77db8d4	1228.47 ms	1248.80 ms	20.33 ms
ccc09e4	1254.74 ms	1277.08 ms	22.34 ms
dd933d4	1238.73 ms	1252.43 ms	13.70 ms
d883d62	1221.39 ms	1230.18 ms	8.80 ms
6034b0a	1244.89 ms	1270.22 ms	25.33 ms

App size

Revision	Plain	With Sentry	Diff
d8f5abb	8.33 MiB	9.40 MiB	1.07 MiB
f275487	8.32 MiB	9.38 MiB	1.05 MiB
fcd1ee4	8.29 MiB	9.36 MiB	1.07 MiB
f7f46dc	8.10 MiB	9.17 MiB	1.08 MiB
ba9c106	8.32 MiB	9.38 MiB	1.06 MiB
77db8d4	8.38 MiB	9.73 MiB	1.35 MiB
ccc09e4	8.16 MiB	9.16 MiB	1.01 MiB
dd933d4	8.33 MiB	9.64 MiB	1.31 MiB
d883d62	8.29 MiB	9.36 MiB	1.07 MiB
6034b0a	8.33 MiB	9.40 MiB	1.07 MiB