Feat: Add `Assignee` Filter to Team Todo List

[Achintya-Chatterjee]

Issue Description

The team's to-do list page cannot currently filter tasks by assignee. Users need a way to filter the list to show tasks assigned to specific team members. This feature is required to improve task management and visibility within teams.

Expected Behaviour

• A Filter button should be added to the team's to-do list page next to the Include Done switch.
• Clicking the Filter button should open a dropdown menu with an Assignee option.
• Clicking Assignee should show a search interface to select users.
• Users should be able to search for team members by name.
• Users should be able to select one or multiple assignees.
• Only users who are part of the current team should be selectable/searchable.
• Selecting assignees should update the task list to show only tasks assigned to the selected users.

Current Behaviour

• The TeamTasks component in src/modules/teams/team-tasks.tsx currently only supports:
  • Include Done toggle (filtering task by status Done).
• There is no UI for filtering tasks by assignee.
• The TasksApi.getTasks method does not pass any assignee-related parameters to the backend.

Screenshots

Reproducibility

• This issue is reproducible
• This issue is not reproducible

Steps to Reproduce

1. Navigate to a Team's Todo List page, e.g., https://todo.realdevsquad.com/teams/68bb3322c9aef0f0bccb5672/todos
2. Observe the available filters in the top bar.
3. You can see that there is no option to filter tasks by `Assignee`.

• Critical
• High
• Medium
• Low

Additional Information

This issue primarily involves:

• Modifying src/modules/teams/team-tasks.tsx to add the filter UI.
• Creating new components for the Filter Menu and Assignee Selection.
• Updating src/api/tasks/tasks.api.ts and src/api/tasks/tasks.types.ts to support passing assigneeId to the backend.
• Ensuring the backend supports this filter (handled in a separate backend issue).

Checklist

• I have read and followed the project's code of conduct.
• I have searched for similar issues before creating this one.
• I have provided all the necessary information to understand and reproduce the issue.
• I am willing to contribute to the resolution of this issue.