[FEATURE] Add an option to turn on and off the certificate validation of MCP connectors

[akolarkunnu]

Is your feature request related to a problem?
Sometimes our MCP external test server will be in private network and need to connect to that by skipping the certificate verification(mainly for easy testing purpose, not for production). So please provide an option to skip certificate verification.

What solution would you like?
We are using java http client for MCP connectors, this is valid for MCP and MCPStreamableHTTP connectors.
Fix will be somewhere here -

ml-commons/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/McpConnectorExecutor.java

Line 86 in 6de6889

McpClientTransport transport = HttpClientSseClientTransport