New Serverless Pattern - Lambda Durable Functions scheduled tasks pattern with workflow orchestration

[agawanea]

Issue #, if available: N/A https://github.com/aws-samples/serverless-patterns/issues/2877

Description of changes: This PR adds a new serverless pattern demonstrating multi-day scheduled task orchestration using AWS Lambda Durable Functions. The pattern implements a 7-day workflow with automatic checkpointing, scheduled waits, and state persistence.

Pattern Components:

Durable Function: Orchestrates 7-day workflow (Day 1: data collection, Days 2-6: batch processing, Day 7: report generation) Task Management Function: Unified function handling GET /tasks, GET /tasks/{id}, and DELETE /tasks DynamoDB: Stores task state and progress API Gateway: RESTful API for task operations Dashboard: Real-time monitoring with auto-refresh and delete functionality

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