Implement Async Functions for API Requests

[AbdoAnss]

Add support for asynchronous operations to improve performance when fetching multiple resources.

Overview

Currently, all API requests are synchronous which can lead to slower performance when fetching multiple resources (players, teams, fixtures etc.). We should implement async versions of key functions to allow concurrent requests.

Proposed Changes

• Add async versions of main service methods
• Implement proper error handling for concurrent requests
• Add rate limiting protection for parallel requests
• Create helper functions for batch operations

Functions to Update

• GetAllPlayers()
• GetPlayerHistory()
• GetAllFixtures()
• GetAllTeams()
• ... etc

Implementation Details

• Use Go routines and channels for concurrent operations
• Implement context support for cancellation
• Maintain existing rate limiting while supporting parallel requests

Success Criteria

• Async versions of key methods implemented
• Proper error handling
• Rate limiting respected
• Tests added for async functions
• Documentation updated

Related

• Rate limiting implementation
• Error handling patterns