[Feature] Add Fork Support to Repository Listing Functionality

[smadi0x86]

Describe the feature or problem you'd like to solve

The current implementation of repository listing functionality in the GitHub MCP server doesn't properly handle forked repositories. When users try to list their repos or other repos they expect to see both their original repositories and their forks, but the current implementation doesn't provide this capability.

Current limitations:

1. Users cannot see their forked repositories in search results
2. Users cannot get a complete list of their repositories including forks
3. Users cannot filter repositories by fork status

Proposed solution

We have two potential approaches to solve this issue:

1. Enhance Search Repositories:

   • Modify the existing search_repositories function to add fork-specific parameters
   • Include fork status in search results
   • Support filtering by fork status

2. Create New Tool for Fork Management:

   • Create a new dedicated tool that lists user's forks specifically
   • Provide fork-specific operations
   • Integrate with existing repository listing functionality

Questions for community input:

1. Which approach would be more beneficial for users, creating an independent tool for listing forks or integrating with search_repositories?
2. Are there specific GitHub API endpoints I should consider or would help in this implementation?

I would like to create a PR to implement the chosen solution after gathering community feedback on the preferred approach and any additional requirements or considerations.