Panic MW: will now return a custom PanicStackError with stack trace

[aldas]

Panic middleware: will now return a custom PanicStackError with stack trace when config.DisablePrintStack is set to false.

relates to #2869 (comment)

[codecov]

Codecov Report

❌ Patch coverage is 60.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.29%. Comparing base (f24aaff) to head (4c630d7).
⚠️ Report is 49 commits behind head on master.

Files with missing lines	Patch %	Lines
middleware/recover.go	60.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2871      +/-   ##
==========================================
+ Coverage   93.25%   93.29%   +0.04%     
==========================================
  Files          39       43       +4     
  Lines        4652     4432     -220     
==========================================
- Hits         4338     4135     -203     
+ Misses        218      179      -39     
- Partials       96      118      +22     

☔ 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.