Implement role management for users on the Admin "Users" page

[RaulBecerraB]

Description:

Problem description:

The Admin "Users" page needs to support role management for each user. Administrators should be able to view and edit user roles by clicking the "Edit" button next to each user in the list.

Tasks:

1. Display user roles:

   • Ensure that each user in the list displays their current role(s) (e.g., Admin, User, etc.).

2. Implement edit functionality:

   • Allow administrators to update user roles via a react-select library.

3. Connect to API:

   • Ensure role updates are sent to the backend via the appropriate API endpoint.
   • Handle success and error states appropriately.

4. UI/UX enhancements:

   • Follow the design guidelines to maintain consistency with the existing Admin panel.
   • Provide visual feedback when a role is successfully updated.

5. Testing:

   • Ensure roles are correctly displayed, edited, and updated.
   • Validate error handling and proper form validation.

Acceptance criteria:

• User roles are displayed on the "Users" page.
• Clicking the "Edit" button opens a form to modify user roles.
• Changes to roles are successfully saved via API.
• The UI matches the design and provides appropriate feedback.
• The implementation is responsive and works across devices.