Add GET Endpoint for Category in Uplift API

[ehsan-nadernezhad]

• Endpoint: GET /api/Category/Get-category
• Functionality: This endpoint should return a list of all categories stored in the database.
• Model: Ensure the Category model includes properties such as Id and Name.
• DbContext: Update the ApplicationDbContext to include DbSet.
• Controller: Create or update the CategoriesController to handle GET requests and return the list of categories.