feat: Update error 413 handling

[bitsandfoxes]

Resolves #4861, getsentry/sentry-unity#2494

[github-actions]

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

Generated by 🚫 dangerJS against 5c48f7b

[bitsandfoxes]

If I read the docs correctly it is expected to now effectively change all NetworkError to SendError, see https://develop.sentry.dev/sdk/expected-features/#dealing-with-network-failures

If Sentry returns an HTTP 4xx or HTTP 5xx status code, SDKs:

MUST discard the envelope
MUST record a [client report](https://develop.sentry.dev/sdk/telemetry/client-reports/) with the discard reason send_error, except for an HTTP 429 response, see below.

[Flash0ver]

I believe you're right.
Disambiguating the dev-docs via getsentry/sentry-docs#16152.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.86%. Comparing base (a2c61d4) to head (5c48f7b).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4863      +/-   ##
==========================================
+ Coverage   73.83%   73.86%   +0.03%     
==========================================
  Files         483      483              
  Lines       17559    17577      +18     
  Branches     3461     3464       +3     
==========================================
+ Hits        12965    12984      +19     
+ Misses       3742     3740       -2     
- Partials      852      853       +1     

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[bitsandfoxes]

@sentry review

[jamescrosswell]

Thanks @bitsandfoxes !