feat: added mr assigned and issues assigned in leaderboard table of each team and overall teams

What does this MR do and why?

This MR adds Issues Assigned and MRs Assigned columns to the Team Leaderboard table and induvidual team leaderboard. The enhancement provides better visibility into task distribution and individual contribution responsibilities, making it easier to track assigned work within the team.

References

Screenshots or screen recordings

References Related to Team Leaderboard feature enhancement Helps improve contribution tracking and team activity visibility