Filtering notes based on categories

[mala-eficode]

Description:

• As a user,
• I want a filter for categories,
• So that I can filter and display items based on their categories.

Acceptance Criteria:

1. Filtering:

   • Categories should be displayed as tabs on the UI.
   • When a category tab is selected, only items belonging to that category should be displayed.

2. Displaying:

   • The filtered items should be displayed in a list or grid format under the selected category tab.
   • The UI should update dynamically to reflect the filtered items when a tab is selected.

3. Testing:

   • Write unit tests to ensure that filtering by category works correctly.