Improve fuzzing for all extensions

[theodorsm]

Description

This PR aims to add fuzz testing of the umarshal functions of all extensions.

[codecov]

Codecov Report

❌ Patch coverage is 56.52174% with 30 lines in your changes missing coverage. Please review.
✅ Project coverage is 82.50%. Comparing base (977de19) to head (1902120).

Files with missing lines	Patch %	Lines
...kg/protocol/extension/supported_elliptic_curves.go	40.00%	5 Missing and 1 partial ⚠️
pkg/protocol/extension/supported_point_formats.go	40.00%	5 Missing and 1 partial ⚠️
pkg/protocol/extension/server_name.go	0.00%	2 Missing and 2 partials ⚠️
pkg/protocol/extension/pre_shared_key.go	0.00%	1 Missing and 2 partials ⚠️
pkg/protocol/extension/alpn.go	50.00%	1 Missing and 1 partial ⚠️
pkg/protocol/extension/certificate_auth.go	66.66%	1 Missing and 1 partial ⚠️
pkg/protocol/extension/post_handshake_auth.go	50.00%	2 Missing ⚠️
pkg/protocol/extension/supported_versions.go	0.00%	1 Missing and 1 partial ⚠️
pkg/protocol/extension/use_master_secret.go	60.00%	2 Missing ⚠️
pkg/protocol/extension/renegotiation_info.go	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #805      +/-   ##
==========================================
- Coverage   82.52%   82.50%   -0.02%     
==========================================
  Files         121      121              
  Lines        6868     6906      +38     
==========================================
+ Hits         5668     5698      +30     
- Misses        786      800      +14     
+ Partials      414      408       -6     

Flag	Coverage Δ
go	82.50% <56.52%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[theodorsm]

The fuzzing discovered multiple discreprencies in how we handle declared length and trailing bytes. Multiple extension parsers does not verify the declared length or extra trailing bytes in the extension data, this PR also fixes that.

[theodorsm]

This PR should also add extended fuzzing for #814 when it's merged. Done, all extension parser fuzzers are now added.

[JoTurk]

Sorry I lost track of this, I'll try to finish my review tonight.