add test coverage for plugin in running server

Problem description

currently there doesn't seem to be any test coverage present which actually starts a server and checks if the plugins work. thus the existing test coverage gives limited information on whether the plugin works before creating a release and manual tests are needed.

Preferred solution

see both the test and yamlRestTest folders for e.g. the analysis-nori plugin which is upstream in both OS & ES:

• OS: https://github.com/opensearch-project/OpenSearch/tree/main/plugins/analysis-nori/src
• ES: https://github.com/elastic/elasticsearch/tree/main/plugins/analysis-nori/src

test tests the plugin infrastructure without starting a full server. the yamlRestTest starts a full server with the plugin installed and runs the tests against the REST API to ensure that the analysis plugin is correctly installed and working.

Alternatives

manually create a server and deploy the plugin.

Additional Information (optional)

n/a