🔥 v3 (feature): Adding GetReqHeaders and GetRespHeaders

[brunodmartins]

Description

Adding GetReqHeaders and GetRespHeaders, that had not been copied from v2 to v3

Fixes #2799

Changes Introduced

Both features and tests (unit and benchamark) were copied and adapted from v2, without major changes.

• Benchmarks: Describe any performance benchmarks and improvements related to the changes.
• Documentation Update: Detail the updates made to the documentation and links to the changed files.
• Changelog/What's New: Include a summary of the additions for the upcoming release notes.
• Migration Guide: If necessary, provide a guide or steps for users to migrate their existing code to accommodate these changes.
• API Alignment with Express: Explain how the changes align with the Express API.
• API Longevity: Discuss the steps taken to ensure that the new or updated APIs are consistent and not prone to breaking changes.
• Examples: Provide examples demonstrating the new features or changes in action.

Type of Change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• Enhancement (improvement to existing features and functionality)
• Documentation update (changes to documentation)
• Performance improvement (non-breaking change which improves efficiency)
• Code consistency (non-breaking change which improves code reliability and robustness)

Checklist

Before you submit your pull request, please make sure you meet these requirements:

• Followed the inspiration of the Express.js framework for new functionalities, making them similar in usage.
• Conducted a self-review of the code and provided comments for complex or critical parts.
• Updated the documentation in the /docs/ directory for Fiber's documentation.
• Added or updated unit tests to validate the effectiveness of the changes or new features.
• Ensured that new and existing unit tests pass locally with the changes.
• Verified that any new dependencies are essential and have been agreed upon by the maintainers/community.
• Aimed for optimal performance with minimal allocations in the new code.
• Provided benchmarks for the new code to analyze and improve upon.

Commit Formatting

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[brunodmartins]

Not related to the PR, but I notice that some tests are randomly failling on gofiber:main..maybe there is a conflict on test execution

[ReneWerner87]

@efectn was there a reason why it was forgotten during the merge? can we implement this pattern better?

[efectn]

@efectn was there a reason why it was forgotten during the merge? can we implement this pattern better?

I suppose i removed them in favor of https://github.com/gofiber/fiber/tree/main/binder#binding-into-the-map. Anyway it will change with #2006. So the PR can be merged