[Feature]: Implement Task Pausing and Resuming

Currently, Bindu agents can start (run) and stop (cancel) tasks, but they cannot pause them. We need a way to support pausing and resuming tasks natively in the framework. This is important for tasks that take a long time, need to wait for external triggers, or require a human to review something before continuing.

I propose adding the missing pause_task and resume_task capabilities to the codebase:

1. The Scheduler (bindu/server/scheduler/base.py): Update it so it can pass pause and resume commands down to the worker.
2. The Worker (bindu/server/workers/base.py): Implement the logic to actually pause and resume the task.
   • Pausing a task will save its current progress to the database, free up memory, and mark it as 'suspended'.
   • Resuming a task will fetch the saved progress from the database, mark it as 'running', and pick up exactly where it left off.

Additional context The placeholder functions for this (_handle_pause and _handle_resume) already exist in the codebase, but they currently just throw a NotImplementedError. Building this feature out will fix a known missing piece of the Agent-to-Agent (A2A) protocol and make our agents much more capable!

@raahulrahl assign this to me!!