AB#122 Feature/122 Create TaskItemRepository

[zhiyizhu805]

Pull Request Title (Mandatory)

• Create TaskItemRepository

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Description (Mandatory)

• What does this PR do?
  Create a ITaskRepository interface and TaskRepository class to implement the CRUD methods.
  Use dbcontext in the TaskRepository.
  Replace the dbcontext by the IRepository in the /tasks controller
  Use DI to inject the interface to the controller.
• Why is this change necessary?
  To implement a repository pattern for better abstraction, maintainability, and testability by injecting ITaskRepository into the TaskItemsController via dependency injection.

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Checklist (Mandatory)

Please ensure your PR meets the following requirements before submitting:

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added or updated relevant documentation (if applicable).
• I have added tests that prove my fix is effective or that my feature works.
• New and existing tests pass locally with my changes.
• I have checked for any potential breaking changes.

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Type of Change (Mandatory)

What kind of change does this PR introduce?
(Please check the relevant options)

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📄 Documentation update (changes to documentation only)
• 🔧 Refactoring (no functional changes, code improvements)

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Approval Checklist for Reviewers

Reviewers, please ensure:

• The code is easy to understand and follows the project's coding standards.
• All required documentation is updated or created.
• The change is appropriately tested and validated.
• There are no breaking changes (or they are clearly documented).

[yanxiaodi]

LGTM. 🚀