Add directive for SSL Server block

[salonichf5]

trafficstars

Proposed changes

Problem: Users want to configure BackendTLS successfully with NGF.

Solution: Adds a directive proxy_ssl_server_name on in the server location block to avoid connection resets during SSL handshake.

Testing: Manual testing by installing NGF and verifying /etc/nginx/nginx.conf

TODO

Please focus on (optional): If you any specific areas where you would like reviewers to focus their attention or provide specific feedback, add them here.

Closes #1836

Checklist

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

• [x] I have read the CONTRIBUTING doc
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] I have checked that all unit tests pass after adding my changes
• [x] I have updated necessary documentation
• [x] I have rebased my branch onto main
• [x] 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.