Adapt disable dn verification on cert reload changes to SSL refactor

[cwperks]

Description

Adapts #4752 to the changes introduced in #4671.

Opening this up in Draft initially while additional testing is performed.

I also opened a revert PR as well to solicit feedback from maintainers on which direction we should take to fix the CI failures.

• Category (Enhancement, New feature, Bug fix, Test fix, Refactoring, Maintenance, Documentation)

Maintenance

Check List

• New functionality includes testing
• New functionality has been documented
• New Roles/Permissions have a corresponding security dashboards plugin PR
• API changes companion pull request created
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 69.90%. Comparing base (eb7f821) to head (d03d83c).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4841      +/-   ##
==========================================
+ Coverage   69.82%   69.90%   +0.08%     
==========================================
  Files         320      320              
  Lines       21661    21674      +13     
  Branches     3456     3457       +1     
==========================================
+ Hits        15124    15151      +27     
+ Misses       4742     4730      -12     
+ Partials     1795     1793       -2     

Files with missing lines	Coverage Δ
...org/opensearch/security/ssl/SslContextHandler.java	98.61% <100.00%> (+0.01%)	⬆️
.../opensearch/security/ssl/config/SslParameters.java	56.94% <100.00%> (+2.53%)	⬆️
...ensearch/security/ssl/util/SSLConfigConstants.java	79.16% <ø> (ø)

... and 6 files with indirect coverage changes

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/security/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/security/backport-2.x
# Create a new branch
git switch --create backport/backport-4841-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 2e0e64f213b85098873e60eb44d133da414dd1a7
# Push it to GitHub
git push --set-upstream origin backport/backport-4841-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/security/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-4841-to-2.x.

[cwperks]

This PR and #4839 need to be backported together.