Add image filter support and complete AWS Cloud Control API schema compliance for guardrails

[farhanashrafdev]

Description

This PR adds comprehensive support for AWS Bedrock Guardrails features, including image content filtering and full AWS Cloud Control API schema compliance.

Type of Change

• New feature (non-breaking change which adds functionality)
• Improvement (enhancement to existing functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Changes Made

Image Filter Support

• Added input_modalities and output_modalities support to filters_config
• Users can now filter both TEXT and IMAGE content types
• Updated examples to demonstrate image filter usage

Type Safety Improvements

• Converted all guardrail config variables from list(map(string)) to properly typed list(object({...}))
• Added all optional fields from AWS Cloud Control API schema
• Improved type safety and IDE autocomplete support

New Features

• Added automated_reasoning_policy_config support
• Added missing optional fields to all guardrail configurations

Resource Configuration

• Improved conditional logic for policy configurations
• Better null handling

Testing

• Verified no linter errors
• Updated examples work correctly
• Backward compatibility maintained (all fields optional)

Checklist

• Code follows the project's style guidelines
• Self-review completed
• Comments added for complex code
• Documentation updated (.header.md)
• No new warnings generated
• Tests pass (if applicable)
• Changes are backward compatible

Related Issues

Closes #161