Attach request body for application/x-www-form-urlencoded requests in Spring

[adinauer]

📜 Description

💡 Motivation and Context

Closes #3656

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code.
• 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.
• 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

[github-actions]

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Generated by 🚫 dangerJS against 72aa792

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	404.12 ms	460.98 ms	56.86 ms
Size	1.70 MiB	2.35 MiB	669.06 KiB

Previous results on branch: feat/spring-request-body-form

Startup times

Revision	Plain	With Sentry	Diff
24c454d	461.16 ms	540.57 ms	79.41 ms

App size

Revision	Plain	With Sentry	Diff
24c454d	1.70 MiB	2.35 MiB	669.06 KiB

[lbloder]

LGTM codewise.
We could extend the SentrySpringFilterTest.caches request depending on the maxRequestBodySize value and request body length to include the new mimetype

[lbloder]

Nice, LGTM 👍