Enhance: support skip_validating_missing_parameters in connector

[yuye-aws]

Description

When using LLM in ml-commons connector, the prompt may contains substring like ${parameters.xxxx} . The PRs adds a parameter named skip_validating_missing_parameters to enable users to configure whether to skip validating missing parameters in payload.

The user can specify this parameter in the following manner:

POST /_plugins/_ml/connectors/_create
{
  "name": "BedRock test connector",
  "description": "The connector to BedRock service for claude model",
  "version": 1,
  "protocol": "aws_sigv4",
  "parameters": {
      "region": "us-east-1",
      "service_name": "bedrock",
      "anthropic_version": "bedrock-2023-05-31",
      "endpoint": "bedrock-runtime.us-east-1.amazonaws.com",
      "auth": "Sig_V4",
      "content_type": "application/json",
      "max_tokens_to_sample": 8000,
      "temperature": 0.00001,
      "skip_validating_missing_parameters": true
  },
  "credential": {
    "access_key": "xxxx",
    "secret_key": "xxxx"
  },
  "actions": [
    {
      "action_type": "predict",
      "method": "POST",
      "url": "https://bedrock-runtime.us-east-1.amazonaws.com/model/anthropic.claude-instant-v1/invoke",
      "headers": { 
        "content-type": "application/json",
        "x-amz-content-sha256": "required"
      },
      "request_body": "{\"prompt\":\"${parameters.prompt}\", \"max_tokens_to_sample\":${parameters.max_tokens_to_sample}, \"temperature\":${parameters.temperature},  \"anthropic_version\":\"${parameters.anthropic_version}\" }"
    }
  ]
}

Related Issues

Resolves #2712

Check List

• New functionality includes testing.
• New functionality has been documented.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

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[yuye-aws]

Please help attach backport 2.x label to this PR. Thanks!

[dhrubo-os]

Is this PR for this RFC?

[yuye-aws]

Is this PR for this RFC?

Yes