[Extension] Build tool for managing extensions

[minalsha]

Is your feature request related to a problem?

Extensions can be installed today, without any tools, its just configuration. With the tools we’ll make it easier to manage extensions. Its nice to have.

[minalsha]

@saratvemulapalli , can you please add details for this issue ? cc @joshpalis

[saratvemulapalli]

Extensions are manually spun up, installed and managed. We'd like to provide a simple tools to manage extensions during it lifecycle.

1. Build a tool which plugs into bin/opensearch[1] and spins up, validates and makes sure the extension is up.
2. As part of the distribution we ship securityadmin.sh[2] the tool should be updated to read extensions.yml config and generate certificates for TLS setup.
3. Similar to bin/opensearch-plugin[3] we should support generating extensions.yml configuration file and put it under extensions directory of opensearch distribution.
4. Build RestAPIs in OpenSearch (ExtensionsManager) to reflect current status/lifecycle of extensions.

[1] https://github.com/opensearch-project/OpenSearch/blob/main/distribution/src/bin/opensearch [2] https://github.com/opensearch-project/security/blob/main/tools/securityadmin.sh [3] https://github.com/opensearch-project/OpenSearch/blob/main/distribution/src/bin/opensearch-plugin