Add AWS Integration support to datadog-sync-cli

[heyronhay]

Summary

This PR implements AWS Integration configuration import functionality for datadog-sync-cli, allowing users to import AWS Integration configurations from source Datadog organizations.

What's Changed

New Features

• New integrations resource type with AWS subtype support (name=aws)
• AWS Integration import command - retrieve configurations by AWS account ID
• Comprehensive filtering support - filter by integration type, account ID, or other attributes

Implementation Details

• Extends BaseResource following existing codebase patterns
• Uses AWS Integration API endpoints (/api/v1/integration/aws)
• Handles multiple API response formats (accounts array, list, single object)
• Implements proper error handling (404, 403, 500 status codes)
• Excludes sensitive fields (secret_access_key) from state files for security
• Supports concurrent processing for performance

Usage Examples

# Import all AWS integrations
datadog-sync import --resources="integrations" \
    --source-api-key="..." --source-app-key="..."

# Import only AWS integrations (with filtering)
datadog-sync import --resources="integrations" \
    --filter='Type=integrations;Name=name;Value=aws' \
    --source-api-key="..." --source-app-key="..."

# Import specific AWS integration by account ID
datadog-sync import --resources="integrations" \
    --filter='Type=integrations;Name=account_id;Value=123456789012' \
    --source-api-key="..." --source-app-key="..."