Add Loading Spinner to Angular Web App

[juhiechandra]

Description:
As a contributor, I want to see a loading spinner when the web app is loading so that I know the page is still loading and not frozen.

Tasks:

• Create a loading spinner component.
• Use a popular UI library such as Bootstrap or Material UI, or create a custom component.
• Add appropriate animations and styles to make it visually appealing.
• Implement the loading spinner in the app.

My Steps:

• Verify that the loading spinner displays and hides correctly.
• Test the spinner with various network conditions (e.g. slow network speeds).
• Include screenshots or gifs of the spinner in action.
• Seek approval from team members.

Feedback from existing codebase:
Use Material UI of Angular.
However as this library is 5 years old, team can certainly decide to use a new UI library.

[juhiechandra]

Note: To pick up this item later