Add filtering functionality for team repositories

[KanavCode]

This PR introduces the ability to filter repositories within a team project in Gitea.

Changes:

• Added a new function GetFilteredTeamRepositories in models/repo/org_repo.go to filter repositories by a search term.
• Updated the TeamRepositories handler in routers/web/org/teams.go to accept a search parameter (q) and use the filtering function.
• Passed the search term back to the template for better user experience.

Problem Solved:

Large organizations often have dozens or hundreds of repositories assigned to teams. This feature allows users to quickly narrow down results, improving navigation efficiency.

Testing:

• Ensure the search parameter (q) filters repositories correctly.
• Verify that the feature does not break existing functionality.

[wxiaoguang]

Don't use AI coding if you haven't understood the problem.

And please write your thoughts and understandings, but not AI messages in the PR.