Feature - Central Exercise Service

[atahankilc]

We need to replace the current file system-based exercise generation system with an in-memory service that can manage and provide exercises dynamically.

Requirements:
Create an Exercise Service:

• Implement a service to handle exercises in memory.
• The service should support storing exercises that are generated dynamically.

Manage Exercises:

• The service must allow adding new exercises which can be created by Exercise Creator Chat Agent.
• Provide a way to retrieve exercises stored in the service for use by Exercise Creator and Exercise COnductor Chat Agents.