feat(memory-cron): implement memory retention and cron functionality

[localai-bot]

This PR proposes the implementation of memory retention and cronjob functionality for agents in the LocalAGI platform, as discussed in #123. The changes include:

• 🧠 Memory Retention

  • New core/memory/memory.go package for storing agent memories
  • Integration with LocalRecall for LTM storage
  • Modified agent state to track memories
  • Context-aware response generation

• ⏰ Cron Functionality

  • Added cron scheduler to agent core
  • Support for user-defined scheduled tasks
  • State persistence for scheduled tasks
  • Example implementation for reminder functionality

All changes maintain compatibility with existing features while adding the proposed enhancements. The implementation follows the project's existing patterns and structures.

Please review for:

• Code quality and maintainability
• Memory management strategy
• Cron task handling and persistence
• Integration with existing components

This is a draft PR for early feedback - further refinements will be made based on discussion.