[Backport 2.x] [Fix #4280] Introduce new endpoint _plugins/_security/api/certificates

[opensearch-trigger-bot]

Backport 382bc5f from #4299. Changed inheritance from TransportRequest to BaseNodeRequest.

[willyborankin]

@cwperks there are plugin install failures. I iwll take a look. Liks like some of PRs have not been backported yet. My bad

[willyborankin]

The PR depends on #4358

[codecov]

Codecov Report

Attention: Patch coverage is 10.66667% with 201 lines in your changes are missing coverage. Please review.

Project coverage is 65.38%. Comparing base (e8b4b3f) to head (6e18f51).

Additional details and impacted files

@@            Coverage Diff             @@
##              2.x    #4355      +/-   ##
==========================================
- Coverage   65.97%   65.38%   -0.59%     
==========================================
  Files         301      309       +8     
  Lines       21588    21812     +224     
  Branches     3514     3543      +29     
==========================================
+ Hits        14242    14262      +20     
- Misses       5585     5786     +201     
- Partials     1761     1764       +3     

Files	Coverage Δ
...security/dlic/rest/api/SecurityRestApiActions.java	80.00% <ø> (ø)
...urity/dlic/rest/api/SecuritySSLCertsApiAction.java	72.46% <100.00%> (+0.40%)	⬆️
...rity/dlic/rest/api/ssl/CertificatesActionType.java	100.00% <100.00%> (ø)
.../opensearch/security/OpenSearchSecurityPlugin.java	84.30% <50.00%> (-0.20%)	⬇️
...h/security/dlic/rest/api/ssl/CertificatesInfo.java	0.00% <0.00%> (ø)
...lic/rest/api/ssl/CertificatesInfoNodesRequest.java	0.00% <0.00%> (ø)
...ch/security/dlic/rest/api/ssl/CertificateType.java	0.00% <0.00%> (ø)
.../security/dlic/rest/api/CertificatesApiAction.java	36.11% <36.11%> (ø)
.../api/ssl/TransportCertificatesInfoNodesAction.java	10.52% <10.52%> (ø)
...ch/security/dlic/rest/api/ssl/CertificateInfo.java	0.00% <0.00%> (ø)
... and 1 more

... and 3 files with indirect coverage changes