Add path-regex annotation for ingress

[jjngx]

Proposed changes

This PR adds support for path-regex annotation for Ingress.
Users can define paths (locations) using one of the following regex annotations:

nginx.org/path-regex: "case_sensitive"
nginx.org/path-regex: "case_insensitive"
nginx.org/path-regex: "exact"

Example ingress resource:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: cafe-ingress
  annotations:
    nginx.org/path-regex: "case_sensitive"
spec:
  ingressClassName: nginx
...

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues found.

Scanned Manifest Files

[codecov]

Codecov Report

Merging #4127 (92a4fa6) into main (0a02259) will increase coverage by 0.06%.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##             main    #4127      +/-   ##
==========================================
+ Coverage   51.84%   51.91%   +0.06%     
==========================================
  Files          59       59              
  Lines       16710    16735      +25     
==========================================
+ Hits         8664     8688      +24     
- Misses       7747     7749       +2     
+ Partials      299      298       -1     

Files Changed	Coverage Δ
internal/configs/annotations.go	23.60% <0.00%> (-0.40%)	⬇️
internal/configs/version1/template_helper.go	100.00% <100.00%> (ø)
internal/k8s/validation.go	93.56% <100.00%> (+0.08%)	⬆️

... and 1 file with indirect coverage changes

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[jasonwilliams14]

Left a few ideas/questions for review.

[shaun-nx]

👍