NGINX Plus R33 support

[sjberman]

Adding support for NGINX Plus R33. The major change with this release is that NGINX Plus now requires a JWT in order to run. A user must create a Secret with this JWT and supply the secret name to NGF when installing. A user can also create client SSL and CA Secrets for NIM connections. All of these Secrets are mounted to the nginx container.

Because of the new usage reporting method, the old usage reporting method has been removed and CLI arguments have been altered. Since this release is a breaking change for N+ users, the choice was made to remove the unused usage reporting flags instead of deprecating them.

Updated documentation to describe this process, while also cleaning up the JWT docker registry process for N+.

Testing: Verified that usage reports are sent when everything is configured properly. Also verified that updates to the Secret are propagated.

Closes #2271
Closes #2709
Closes #2759

Original PR: #2728

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

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

Dev note: This should require a full section at the top of the CHANGELOG for breaking changes. The docs link here is invalid until the release goes out.

NGINX Plus R33 support added. This release of NGINX Plus requires a valid JSON Web Token (JWT) in order to run. Users of NGINX Plus *must* have this JWT added to a Secret before installing NGINX Gateway Fabric v1.5.0. See the [NGINX Plus JWT](https://docs.nginx.com/nginx-gateway-fabric/installation/nginx-plus-jwt/) guide for information on setting this up.

[github-actions]

✅ Deploy Preview will be available once build job completes!

Name	Link
😎 Deploy Preview	https://frontdoor-test-docs.nginx.com/previews/nginx-gateway-fabric/2760/

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[codecov]

Codecov Report

Attention: Patch coverage is 83.45865% with 66 lines in your changes missing coverage. Please review.

Project coverage is 89.86%. Comparing base (64e93a2) to head (7995b71).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/gateway/commands.go	74.52%	24 Missing and 3 partials ⚠️
internal/mode/static/manager.go	74.44%	23 Missing ⚠️
internal/mode/static/handler.go	86.04%	4 Missing and 2 partials ⚠️
cmd/gateway/validation.go	91.42%	2 Missing and 1 partial ⚠️
internal/mode/static/nginx/config/main_config.go	95.58%	1 Missing and 2 partials ⚠️
internal/mode/static/nginx/file/folders.go	33.33%	1 Missing and 1 partial ⚠️
internal/mode/static/state/graph/graph.go	86.66%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2760      +/-   ##
==========================================
+ Coverage   89.40%   89.86%   +0.46%     
==========================================
  Files         110      107       -3     
  Lines       10913    10997      +84     
  Branches       50       50              
==========================================
+ Hits         9757     9883     +126     
+ Misses       1098     1054      -44     
- Partials       58       60       +2     

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[ADubhlaoich]

LGTM. The documentation changes are very thorough and complete: I have some minor edit suggestions.