Add TLS configuration settings/endpoints for auxiliary transports

[finnegancarroll]

Description

Add settings for configuring TLS resources for optional auxiliary client/server transports in OpenSearch core which are supplied and registered by plugins.

Auxiliary transport settings/keys/certificates are distinct from http settings as:

• Aux transports may not be http based
• Users may want security settings for their aux transports separate from http

Added settings mirror existing http configuration options with exception:

• Aux transports are disabled by default since they are optional

Issues Resolved

#5104

Do these changes introduce new permission(s) to be displayed in the static dropdown on the front-end? If so, please open a draft PR in the security dashboards plugin and link the draft PR here

Testing

[Please provide details of testing done: unit testing, integration testing and manual testing]

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

Attention: Patch coverage is 70.51282% with 23 lines in your changes missing coverage. Please review.

Project coverage is 71.68%. Comparing base (305df57) to head (04ba906).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
...rg/opensearch/security/ssl/SslSettingsManager.java	79.62%	4 Missing and 7 partials ⚠️
.../opensearch/security/ssl/config/SslParameters.java	21.42%	11 Missing ⚠️
...ensearch/security/ssl/util/SSLConfigConstants.java	83.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5152      +/-   ##
==========================================
+ Coverage   71.64%   71.68%   +0.04%     
==========================================
  Files         335      335              
  Lines       22748    22803      +55     
  Branches     3599     3607       +8     
==========================================
+ Hits        16297    16346      +49     
- Misses       4651     4655       +4     
- Partials     1800     1802       +2     

Files with missing lines	Coverage Δ
...arch/security/ssl/OpenSearchSecuritySSLPlugin.java	87.24% <100.00%> (ø)
...a/org/opensearch/security/ssl/config/CertType.java	100.00% <100.00%> (ø)
...opensearch/security/ssl/util/SSLRequestHelper.java	66.98% <100.00%> (ø)
...ensearch/security/ssl/util/SSLConfigConstants.java	80.76% <83.33%> (+1.60%)	⬆️
...rg/opensearch/security/ssl/SslSettingsManager.java	74.66% <79.62%> (+1.58%)	⬆️
.../opensearch/security/ssl/config/SslParameters.java	53.84% <21.42%> (-3.10%)	⬇️

... and 7 files with indirect coverage changes

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