Refactor: Improve Code Readability with Constants and Early Returns

[k-vanio]

Refactor: Improve Code Readability with Constants and Early Returns

This commit refactors the realIP function by introducing constants for header names
(trueClientIP, xRealIP, xForwardedFor) to enhance code clarity. Additionally, it
utilizes the concept of early returns for simplifying the logic and improving overall
readability.

These changes contribute to better maintainability and understanding of the codebase.

[lesichkovm]

@k-vanio, you have done good job, two points:

1. The constants should be alphabetically sorted to improve readability
2. You have missed the net.ParseIP(ip) logic which was checking the IP for validity

[k-vanio]

@lesichkovm Thank you for your feedback! I've addressed the first point by alphabetically sorting the constants. However, regarding the second point about the net.ParseIP(ip) logic, I couldn't identify any issues with it as it seems correct to me. Could you please provide more details or context about what you've observed?

[lesichkovm]

Did not see the new function isValidIP. All is good @k-vanio

[VojtechVitek]

LGTM

[PauloRobertTlss]

LGTM 🚀

[VojtechVitek]

Hi @k-vanio,

Thanks for the Pull Request and sorry it did't get merged to the master branch.

I decided to merge the following PR instead, which adds a new feature and also improves modularity and readability at the same time:

Superseded by #908.

Best,
Vojtech